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Page No 157:

Question 1:

Answer:

(i) CP = Rs. 950
Gain = 6%
 
  SP ={(100 + Gain%)100× CP } = {(100 + 6)100× 950} = 106100× 950 = 100700100 = Rs. 1007


   (ii) CP = Rs. 9600
Gain = 1623% = 50 3%
   
        SP={ (100 + Gain%)100× CP} = {(100 + 503)100× 9600} = 350300 ×9600 = 33603 = Rs. 11200


  (iii) CP = Rs. 1540
Loss = 4%
       
        SP={(100 - Loss%)100× CP} = {(100 - 4)100× 1540} = 96100× 1540 = 147840100 = Rs. 1478.40


(iv) CP = Rs. 8640  
Loss = 1212% = 252%
     
  SP={(100 - Loss%)100× CP} = {(100 - 252)100× 8640} = 175200× 8640 = 1512000200 = Rs. 7560

Page No 157:

Question 2:

(i) CP = Rs. 950
Gain = 6%
 
  SP ={(100 + Gain%)100× CP } = {(100 + 6)100× 950} = 106100× 950 = 100700100 = Rs. 1007


   (ii) CP = Rs. 9600
Gain = 1623% = 50 3%
   
        SP={ (100 + Gain%)100× CP} = {(100 + 503)100× 9600} = 350300 ×9600 = 33603 = Rs. 11200


  (iii) CP = Rs. 1540
Loss = 4%
       
        SP={(100 - Loss%)100× CP} = {(100 - 4)100× 1540} = 96100× 1540 = 147840100 = Rs. 1478.40


(iv) CP = Rs. 8640  
Loss = 1212% = 252%
     
  SP={(100 - Loss%)100× CP} = {(100 - 252)100× 8640} = 175200× 8640 = 1512000200 = Rs. 7560

Answer:

(i) CP = Rs. 2400  
SP = Rs. 2592
    Gain = SP - CP = Rs. ( 2592 - 2400) = Rs. 192
 
    Gain%  = GainCP × 100 = 1922400× 100 = 8

(ii) CP = Rs. 1650  
SP = Rs. 1452
    Loss = CP - SP = ( 1650 - 1452) = Rs. 198
   
     Loss%  = LossCP × 100 =1981650 × 100 = 12 

(iii) CP = Rs. 12000   and   SP = Rs. 12800
    Gain = SP - CP = ( 12800 - 12000) = Rs. 800
   
     Gain% = GainCP × 100 = 80012000× 100 = 6.66


(iv) CP = Rs. 1800  
SP = Rs. 1611
     Loss = CP - SP = ( 1800 - 1611) = Rs. 189
 
       Loss% = LossCP × 100 =1891800 × 100 = 10.5 

Page No 157:

Question 3:

(i) CP = Rs. 2400  
SP = Rs. 2592
    Gain = SP - CP = Rs. ( 2592 - 2400) = Rs. 192
 
    Gain%  = GainCP × 100 = 1922400× 100 = 8

(ii) CP = Rs. 1650  
SP = Rs. 1452
    Loss = CP - SP = ( 1650 - 1452) = Rs. 198
   
     Loss%  = LossCP × 100 =1981650 × 100 = 12 

(iii) CP = Rs. 12000   and   SP = Rs. 12800
    Gain = SP - CP = ( 12800 - 12000) = Rs. 800
   
     Gain% = GainCP × 100 = 80012000× 100 = 6.66


(iv) CP = Rs. 1800  
SP = Rs. 1611
     Loss = CP - SP = ( 1800 - 1611) = Rs. 189
 
       Loss% = LossCP × 100 =1891800 × 100 = 10.5 

Answer:

(i) SP = Rs. 924  
Gain = 10%
   
   CP ={ 100(100 + Gain%)× SP} 

={100(100 + 10)× 924} = 92400110 = Rs. 840


(ii) SP = Rs. 1755  
Gain = 1212% =252%
 
     CP = {100(100 + Gain%)× SP} ={100(100 + 252)× 1755} =  {200225× 1755} = 351000225 = Rs. 1560

                                 
(iii) SP = Rs. 8510  
Loss = 8%
       
      CP = {100(100 - Loss%)× SP} = {100(100 - 8 )× 8510} = 85100092= Rs. 9250
 

(iv) SP = Rs. 5600  
Loss = 623% = 203%
     
     CP = {100(100 - Loss%)× SP} = {100(100 - 203)×5600} = {300280× 5600} = 16800028 = Rs. 6000

Page No 157:

Question 4:

(i) SP = Rs. 924  
Gain = 10%
   
   CP ={ 100(100 + Gain%)× SP} 

={100(100 + 10)× 924} = 92400110 = Rs. 840


(ii) SP = Rs. 1755  
Gain = 1212% =252%
 
     CP = {100(100 + Gain%)× SP} ={100(100 + 252)× 1755} =  {200225× 1755} = 351000225 = Rs. 1560

                                 
(iii) SP = Rs. 8510  
Loss = 8%
       
      CP = {100(100 - Loss%)× SP} = {100(100 - 8 )× 8510} = 85100092= Rs. 9250
 

(iv) SP = Rs. 5600  
Loss = 623% = 203%
     
     CP = {100(100 - Loss%)× SP} = {100(100 - 203)×5600} = {300280× 5600} = 16800028 = Rs. 6000

Answer:

Cost price of an almirah = Rs. 13600
Transportation cost = Rs. 400
Total cost price = Rs. (13600 + 400) = Rs. 14000
Selling price = Rs. 16800
Now, SP > CP
Gain = SP - CP = ( 16800 - 14000) = Rs. 2800

Gain% = GainCP× 100 %

=280014000× 100%

=2800140% = 20%

Page No 157:

Question 5:

Cost price of an almirah = Rs. 13600
Transportation cost = Rs. 400
Total cost price = Rs. (13600 + 400) = Rs. 14000
Selling price = Rs. 16800
Now, SP > CP
Gain = SP - CP = ( 16800 - 14000) = Rs. 2800

Gain% = GainCP× 100 %

=280014000× 100%

=2800140% = 20%

Answer:

Cost price of the house = Rs. 765000
Cost  of repairing the house = Rs. 115000
Total Cost price = (765000 + 115000) = Rs. 880000
Ravi sold it at a gain of 5%.

 SP= {(100 + gain %)100× CP}= {(100 + 5)100× 880000} = 105100× 880000 = Rs. 924000

 He gets Rs. 924000.

Page No 157:

Question 6:

Cost price of the house = Rs. 765000
Cost  of repairing the house = Rs. 115000
Total Cost price = (765000 + 115000) = Rs. 880000
Ravi sold it at a gain of 5%.

 SP= {(100 + gain %)100× CP}= {(100 + 5)100× 880000} = 105100× 880000 = Rs. 924000

 He gets Rs. 924000.

Answer:

CP of 12 lemons (dozen) = Rs. 25
CP of one lemon = Rs. 2512

CP of five lemons = 5 â€‹× 2512 = 12512 = Rs. 10.42

SP of five lemons = Rs. 12            (given)

Gain = SP - CP = ( 12 - 10.42 ) = Rs 1.58

Gain% =GainCP× 100%

=1.5810.42 × 100 %

= 15.2%

Page No 157:

Question 7:

CP of 12 lemons (dozen) = Rs. 25
CP of one lemon = Rs. 2512

CP of five lemons = 5 â€‹× 2512 = 12512 = Rs. 10.42

SP of five lemons = Rs. 12            (given)

Gain = SP - CP = ( 12 - 10.42 ) = Rs 1.58

Gain% =GainCP× 100%

=1.5810.42 × 100 %

= 15.2%

Answer:

Let the cost price of the pen be Re 1.
Cost price of 12 pens = Rs 12
SP of 12 pens = CP of 15 pens = Rs 15
Gain = SP - CP = Rs (15 - 12) = Rs 3

Gain% = GainCP× 100 %

=312× 100 %= 25%

Gain% = 25%

Page No 157:

Question 8:

Let the cost price of the pen be Re 1.
Cost price of 12 pens = Rs 12
SP of 12 pens = CP of 15 pens = Rs 15
Gain = SP - CP = Rs (15 - 12) = Rs 3

Gain% = GainCP× 100 %

=312× 100 %= 25%

Gain% = 25%

Answer:

Let the cost price of one spoon be Re 1.
CP of 16 spoons = Rs 16
SP of 16 spoons = CP of 15 spoons = Rs 15
Loss = CP - SP = (16 - 15) = Re 1

Loss% = LossCP× 100% = 116× 100 %=6.25%

Loss% = 6.25%

Page No 157:

Question 9:

Let the cost price of one spoon be Re 1.
CP of 16 spoons = Rs 16
SP of 16 spoons = CP of 15 spoons = Rs 15
Loss = CP - SP = (16 - 15) = Re 1

Loss% = LossCP× 100% = 116× 100 %=6.25%

Loss% = 6.25%

Answer:

Cost price of a video = Rs. 12000
SP of a video at a gain of 10% ={(100 + Gain%)100× CP} 

 ={(100 + 10)100× 12000} = {110100× 12000} = Rs.13200

So, Rahul purchased at a cost price of Rs. 13200.

Rahul sells it at a loss of 5%.

SP of a video at loss of 5% = {(100 - Loss%)100× CP} 

={(100 - 5)100× 13200} = 95100× 13200 = Rs. 12540

∴ Rakesh pays = Rs. 12540

Page No 157:

Question 10:

Cost price of a video = Rs. 12000
SP of a video at a gain of 10% ={(100 + Gain%)100× CP} 

 ={(100 + 10)100× 12000} = {110100× 12000} = Rs.13200

So, Rahul purchased at a cost price of Rs. 13200.

Rahul sells it at a loss of 5%.

SP of a video at loss of 5% = {(100 - Loss%)100× CP} 

={(100 - 5)100× 13200} = 95100× 13200 = Rs. 12540

∴ Rakesh pays = Rs. 12540

Answer:

SP of the sofa set = Rs. 21600
Gain% = 8

 CP of the sofa set={100(100 + Gain%)×SP} = {100(100 + 8)× 21600} = 2160000108 = Rs. 20000

He purchased it at the cost of Rs. 20000.

Page No 157:

Question 11:

SP of the sofa set = Rs. 21600
Gain% = 8

 CP of the sofa set={100(100 + Gain%)×SP} = {100(100 + 8)× 21600} = 2160000108 = Rs. 20000

He purchased it at the cost of Rs. 20000.

Answer:

SP of the watch = Rs 11400
Loss% = 5

CP = {100(100 - Loss%)× SP} 

={100(100 - 5)× 11400} = 1140095 = Rs. 12000

 He purchased it at the cost of Rs. 12000.

Page No 157:

Question 12:

SP of the watch = Rs 11400
Loss% = 5

CP = {100(100 - Loss%)× SP} 

={100(100 - 5)× 11400} = 1140095 = Rs. 12000

 He purchased it at the cost of Rs. 12000.

Answer:

SP of the calculator = Rs. 1325
Gain % = 6

CP of the calculator = {100(100 + Gain%)× SP} 

={100(100 + 6)×1325} = 132500106 = Rs. 1250
             
 SP of the calculator= {(100 + Gain%)100× CP} = {(100 + 12)100× 1250} = 140000100 = Rs.1400

Page No 157:

Question 13:

SP of the calculator = Rs. 1325
Gain % = 6

CP of the calculator = {100(100 + Gain%)× SP} 

={100(100 + 6)×1325} = 132500106 = Rs. 1250
             
 SP of the calculator= {(100 + Gain%)100× CP} = {(100 + 12)100× 1250} = 140000100 = Rs.1400

Answer:

SP of a computer = Rs. 24480
Loss% = 4
  
CP of the computer={100(100 - Loss%)× SP} = {100(100 - 4)× 24480} = 244800096= Rs. 25500

In order to gain 4%:
   SP of the computer={(100 + Gain%)100× CP} = {(100 + 4)100× 25500} = {104100× 25500} = 2652000100 = Rs. 26520                                                                            
                           

Page No 157:

Question 14:

SP of a computer = Rs. 24480
Loss% = 4
  
CP of the computer={100(100 - Loss%)× SP} = {100(100 - 4)× 24480} = 244800096= Rs. 25500

In order to gain 4%:
   SP of the computer={(100 + Gain%)100× CP} = {(100 + 4)100× 25500} = {104100× 25500} = 2652000100 = Rs. 26520                                                                            
                           

Answer:

Let the CP of the tricycle be Rs. x

SP at 15% gain = {(100 + Gain%)100× CP} 
={(100 + 15)100× x} = 115100x 

=Rs. 2320x

SP at 20% gain = x × 120100 = Rs. 65x



65x-2320x=10824x-23x20=108x20=108x=2160

Hence, the cost price of the tricycle is Rs. 2160

Page No 157:

Question 15:

Let the CP of the tricycle be Rs. x

SP at 15% gain = {(100 + Gain%)100× CP} 
={(100 + 15)100× x} = 115100x 

=Rs. 2320x

SP at 20% gain = x × 120100 = Rs. 65x



65x-2320x=10824x-23x20=108x20=108x=2160

Hence, the cost price of the tricycle is Rs. 2160

Answer:

Let CP of  a television be Rs x.
SP at 8% loss =  (100 - 8)100× x = Rs. 92100x
                     100
SP at 6% gain =     (100 + 6)100× x = Rs. 106100x                                                      

      106100x - 92100x = 3360                                                                                       
 
                       ⇒14100x = 3360                                                                                             
                                                                          
                        ⇒         x = 33600014 = 24000                                                                 

∴ CP = Rs. 24000
Sandeep bought it at the cost of Rs. 24000.

Page No 157:

Question 16:

Let CP of  a television be Rs x.
SP at 8% loss =  (100 - 8)100× x = Rs. 92100x
                     100
SP at 6% gain =     (100 + 6)100× x = Rs. 106100x                                                      

      106100x - 92100x = 3360                                                                                       
 
                       ⇒14100x = 3360                                                                                             
                                                                          
                        ⇒         x = 33600014 = 24000                                                                 

∴ CP = Rs. 24000
Sandeep bought it at the cost of Rs. 24000.

Answer:

SP of each cycle = Rs. 2376
He gains 10% in one cycle.
CP = {100(100 + Gain%)× SP} 
 ={100(100 + 10) × 2376} = 100110× 2376 = Rs. 2160

He looses 10% in the second cycle.
CP = 100(100 - Loss%) × SP

=100(100 - 10)× 2376= 10090× 2376 = 237609 = Rs. 2640

Total CP = Rs. ( 2160 + 2640 ) = Rs. 4800                                                                            
Total SP =    Rs. ( 2376 + 2376 ) = Rs. 4752                                                                         
 Loss = CP - SP = Rs. ( 4800 - 4752 ) = Rs. 48
    Loss%  = LossCP× 100%
=484800 × 100% = 1%

Page No 157:

Question 17:

SP of each cycle = Rs. 2376
He gains 10% in one cycle.
CP = {100(100 + Gain%)× SP} 
 ={100(100 + 10) × 2376} = 100110× 2376 = Rs. 2160

He looses 10% in the second cycle.
CP = 100(100 - Loss%) × SP

=100(100 - 10)× 2376= 10090× 2376 = 237609 = Rs. 2640

Total CP = Rs. ( 2160 + 2640 ) = Rs. 4800                                                                            
Total SP =    Rs. ( 2376 + 2376 ) = Rs. 4752                                                                         
 Loss = CP - SP = Rs. ( 4800 - 4752 ) = Rs. 48
    Loss%  = LossCP× 100%
=484800 × 100% = 1%

Answer:

Let the CP of the exhaust fan be Rs. x.
Gain = Rs. x6           

​SP =  Rs ( x + x6)  
     
SP = Rs. 7350               

∴     x + x6 = 7350
 ⇒    76x = 7350
⇒        x = 7350 × 67 = 441007 =6300
CP of the fan = Rs. 6300

Page No 157:

Question 18:

Let the CP of the exhaust fan be Rs. x.
Gain = Rs. x6           

​SP =  Rs ( x + x6)  
     
SP = Rs. 7350               

∴     x + x6 = 7350
 ⇒    76x = 7350
⇒        x = 7350 × 67 = 441007 =6300
CP of the fan = Rs. 6300

Answer:

Mohit sold a watch to Karim at Rs. x.
Mohit sold it at a gain of 10%.
SP of the watch = 110% of x
                  =  (x + 110100) = Rs. 1120x                                                                        
Karim sold it to Rahim at a gain of 4%.
SP of the watch = 104% of 1110x =  (104100 × 1110x) = Rs. (2625× 1110x)                                                       
                                                                                                    
But, Rahim pays Rs. 14300.
∴ 2625× 1110x = 14300                                                                                                            

x = 14300 × 25 × 1026 × 11 =3575000286 =12500

Mohit purchased it at Rs. 25000.

Page No 157:

Question 19:

Mohit sold a watch to Karim at Rs. x.
Mohit sold it at a gain of 10%.
SP of the watch = 110% of x
                  =  (x + 110100) = Rs. 1120x                                                                        
Karim sold it to Rahim at a gain of 4%.
SP of the watch = 104% of 1110x =  (104100 × 1110x) = Rs. (2625× 1110x)                                                       
                                                                                                    
But, Rahim pays Rs. 14300.
∴ 2625× 1110x = 14300                                                                                                            

x = 14300 × 25 × 1026 × 11 =3575000286 =12500

Mohit purchased it at Rs. 25000.

Answer:

Let the production cost of a washing machine be Rs. x.
Profit of the manufacturer  = 10%
SP of the manufacturer = 110% of x
                                    =  (x + 110100) = 110100x = Rs. 1110                                                             
Profit of the wholesale dealer = 15%
SP of the wholesale dealer =   115% of Rs 1110x                                           
                                        = Rs (1110x × 115100) = Rs (1110x × 2320)
                                           
Profit of the retailer = 25%
SP of the retailer = 125% of Rs (1110x × 2320)     
                          
                          = Rs. ( 1110x × 2320×125100) = Rs. (1110x × 2320× 54)
                                
Given:
Retail price = Rs. 37950
∴ (1110x × 2320 × 54) = 37950
                                                                                                  
                            x = 37950 × 10 × 20 × 411 × 23 × 5 
=> x= 303600001265 = 24000                                                          
                                      
∴ Production cost of a washing machine = Rs. 24000

Page No 157:

Question 20:

Let the production cost of a washing machine be Rs. x.
Profit of the manufacturer  = 10%
SP of the manufacturer = 110% of x
                                    =  (x + 110100) = 110100x = Rs. 1110                                                             
Profit of the wholesale dealer = 15%
SP of the wholesale dealer =   115% of Rs 1110x                                           
                                        = Rs (1110x × 115100) = Rs (1110x × 2320)
                                           
Profit of the retailer = 25%
SP of the retailer = 125% of Rs (1110x × 2320)     
                          
                          = Rs. ( 1110x × 2320×125100) = Rs. (1110x × 2320× 54)
                                
Given:
Retail price = Rs. 37950
∴ (1110x × 2320 × 54) = 37950
                                                                                                  
                            x = 37950 × 10 × 20 × 411 × 23 × 5 
=> x= 303600001265 = 24000                                                          
                                      
∴ Production cost of a washing machine = Rs. 24000

Answer:

Mr. Mehta purchased a video at the cost of Rs. 20000.
Mr. Mehta purchased a television at the cost of Rs. 30000.
Total cost = Rs. (20000 + 30000) = Rs. 50000

He lost 5% on the video.

SP= (100-Loss%)100×CP=100-5100×20000=95100×20000=Rs. 19000   
                                                 
He gained 8% on the television.

SP= (100+Gain%)100×CP=100+8100×30000=108100×30000=Rs. 32400
                                                                                 
Total SP =  Rs. ( 190000 + 32400 ) = Rs. 51400     
                                                                                
Total CP = Rs. 50000
Total Gain = SP - CP = Rs. ( 51400 - 50000 ) = Rs. 1400                                                     
Gain% = GainCP× 100 %=  140050000 × 100% = 2.8%



Page No 158:

Question 21:

Mr. Mehta purchased a video at the cost of Rs. 20000.
Mr. Mehta purchased a television at the cost of Rs. 30000.
Total cost = Rs. (20000 + 30000) = Rs. 50000

He lost 5% on the video.

SP= (100-Loss%)100×CP=100-5100×20000=95100×20000=Rs. 19000   
                                                 
He gained 8% on the television.

SP= (100+Gain%)100×CP=100+8100×30000=108100×30000=Rs. 32400
                                                                                 
Total SP =  Rs. ( 190000 + 32400 ) = Rs. 51400     
                                                                                
Total CP = Rs. 50000
Total Gain = SP - CP = Rs. ( 51400 - 50000 ) = Rs. 1400                                                     
Gain% = GainCP× 100 %=  140050000 × 100% = 2.8%

Answer:

Let the CP of 1 orange be Rs. x.
∴ CP of 36 oranges = Rs. 36x
Let SP of orange be Rs. y.
∴ SP of 36 oranges = Rs. 36y

​Loss = SP of 4 oranges = 4y      (given)

We know:
Loss = CP - SP 
         ⇒            4y = 36x - 36y
        ⇒            4y + 36y = 36x  
        ⇒                      40y = 36x
        ⇒                         10y = 9x
​        ⇒                             y = 910x 
                              
 Loss% = LossCP×100 %

=4y36x× 100 %

=4 × 9x36x× 10× 100% = 10%
  
​Loss% = 10%

Page No 158:

Question 22:

Let the CP of 1 orange be Rs. x.
∴ CP of 36 oranges = Rs. 36x
Let SP of orange be Rs. y.
∴ SP of 36 oranges = Rs. 36y

​Loss = SP of 4 oranges = 4y      (given)

We know:
Loss = CP - SP 
         ⇒            4y = 36x - 36y
        ⇒            4y + 36y = 36x  
        ⇒                      40y = 36x
        ⇒                         10y = 9x
​        ⇒                             y = 910x 
                              
 Loss% = LossCP×100 %

=4y36x× 100 %

=4 × 9x36x× 10× 100% = 10%
  
​Loss% = 10%

Answer:

Let the CP of one pencil be Rs. x.
Therefore, the CP of 96 pencils will be Rs. 96x.
Let SP of one pencil be Rs. y.
​∴ SP of 96 pencils = Rs. 96y
Gain= SP of one dozen pencil = Rs.12y           (given)

Gain = SP - CP 

       12y=96y-96x96x=96y-12y96x=84yx=84y96
                              
 Gain% = GainCP×100 %=12y96x×100%=12y×9696×84y×100%=14.28%

Page No 158:

Question 1:

Let the CP of one pencil be Rs. x.
Therefore, the CP of 96 pencils will be Rs. 96x.
Let SP of one pencil be Rs. y.
​∴ SP of 96 pencils = Rs. 96y
Gain= SP of one dozen pencil = Rs.12y           (given)

Gain = SP - CP 

       12y=96y-96x96x=96y-12y96x=84yx=84y96
                              
 Gain% = GainCP×100 %=12y96x×100%=12y×9696×84y×100%=14.28%

Answer:

(b) 25%

CP of the book = Rs. 80
SP of the book = Rs. 100
Gain = SP - CP = Rs. (100 - 80) = Rs. 20
Gain% = GainCP× 100 %= 2080× 100 %= 25%

Page No 158:

Question 2:

(b) 25%

CP of the book = Rs. 80
SP of the book = Rs. 100
Gain = SP - CP = Rs. (100 - 80) = Rs. 20
Gain% = GainCP× 100 %= 2080× 100 %= 25%

Answer:

(a) 1212%

CP of a football = Rs. 120
SP of a football = Rs. 105

CP>SP
∴ Loss = CP - SP = Rs. ( 120 - 105 ) = Rs. 15
Loss% = LossCP × 100%= 15120× 100 %= 252 %= 1212%

Page No 158:

Question 3:

(a) 1212%

CP of a football = Rs. 120
SP of a football = Rs. 105

CP>SP
∴ Loss = CP - SP = Rs. ( 120 - 105 ) = Rs. 15
Loss% = LossCP × 100%= 15120× 100 %= 252 %= 1212%

Answer:

(b) 25%

SP of the bat = Rs. 100
Gain = Rs. 20

 Gain = SP - CP 
     ⇒    20  = 100 - CP
    ⇒   CP = 100 - 20 = Rs. 80

Gain% = GainCP× 100 %=2080× 100% = 25%

Page No 158:

Question 4:

(b) 25%

SP of the bat = Rs. 100
Gain = Rs. 20

 Gain = SP - CP 
     ⇒    20  = 100 - CP
    ⇒   CP = 100 - 20 = Rs. 80

Gain% = GainCP× 100 %=2080× 100% = 25%

Answer:

(a) Rs. 180

SP of the racket = Rs. 198
Gain% = 10
  
CP of the racket={100(100 + Gain%)× 100} = {100(100 + 10)× 198} =100110× 198 = Rs. 180

Page No 158:

Question 5:

(a) Rs. 180

SP of the racket = Rs. 198
Gain% = 10
  
CP of the racket={100(100 + Gain%)× 100} = {100(100 + 10)× 198} =100110× 198 = Rs. 180

Answer:

Let the cost price be Rs. x.
 Loss = Rs. x7
∴  SP =   (x - x7) = Rs. 67x                                                                

Given:
SP = Rs. 144  

∴  67x = 144 
⇒ x = 144 × 76 =Rs. 168

∴ CP = Rs. 168
SP = Rs. 144

New SP = Rs. 189
Gain = SP - CP = Rs. ( 189 - 168 ) = Rs. 21     
                     
Gain% = GainCP× 100%= 21168× 100%=12.5%

The correct answer is 12.5%.
All the given options are wrong.

Page No 158:

Question 6:

Let the cost price be Rs. x.
 Loss = Rs. x7
∴  SP =   (x - x7) = Rs. 67x                                                                

Given:
SP = Rs. 144  

∴  67x = 144 
⇒ x = 144 × 76 =Rs. 168

∴ CP = Rs. 168
SP = Rs. 144

New SP = Rs. 189
Gain = SP - CP = Rs. ( 189 - 168 ) = Rs. 21     
                     
Gain% = GainCP× 100%= 21168× 100%=12.5%

The correct answer is 12.5%.
All the given options are wrong.

Answer:

(d) Rs. 72

SP of the pen = Rs. 48
Loses = 20%
Then , CP = {100(100 - Loss%)× SP} 
={100(100 - 20)× 48}= Rs. 60

In order to gain 20%:

SP = {(100 + Gain%)100× CP} = {(100 + 20)100× 60} = 120100× 60 = Rs. 72

Page No 158:

Question 7:

(d) Rs. 72

SP of the pen = Rs. 48
Loses = 20%
Then , CP = {100(100 - Loss%)× SP} 
={100(100 - 20)× 48}= Rs. 60

In order to gain 20%:

SP = {(100 + Gain%)100× CP} = {(100 + 20)100× 60} = 120100× 60 = Rs. 72

Answer:

(a) 20%

Let the cost price of each pencil be Rs.1
Cost of 15 pencils = Rs 15
SP of 15 pencil = CP of 12 pencil = Rs 12
∴ CP = Rs 15
    SP = Rs 12

Loss = CP - SP =  Rs (15 -12) = Rs 3                                         

Loss% = LossCP× 100 %= 315× 100% = 300 15%= 20%

Page No 158:

Question 8:

(a) 20%

Let the cost price of each pencil be Rs.1
Cost of 15 pencils = Rs 15
SP of 15 pencil = CP of 12 pencil = Rs 12
∴ CP = Rs 15
    SP = Rs 12

Loss = CP - SP =  Rs (15 -12) = Rs 3                                         

Loss% = LossCP× 100 %= 315× 100% = 300 15%= 20%

Answer:

(d) 3313%

Let the cost price of each toffee be Rs. 1
Cost price of three toffees = Rs 3
SP of three toffees = CP of four toffees =  Rs 4

CP = Rs 3  
SP = Rs 4

Gain = SP - CP = Rs ( 4 - 3 ) = Re 1
Gain% = GainCP× 100% = 13× 100 %=1003% =3313%

Page No 158:

Question 9:

(d) 3313%

Let the cost price of each toffee be Rs. 1
Cost price of three toffees = Rs 3
SP of three toffees = CP of four toffees =  Rs 4

CP = Rs 3  
SP = Rs 4

Gain = SP - CP = Rs ( 4 - 3 ) = Re 1
Gain% = GainCP× 100% = 13× 100 %=1003% =3313%

Answer:

(c) Rs. 176

SP of an article = Rs. 144 
Loss% = 10
CP = {100(100 - Loss%)× SP} = {100(100 - 10)× 144} = 10090× 144 = 14409= Rs. 160


In order to gain 10%:

S.P. = (100 + Gain%)100× CP= (100 + 10)100× 160= 110100× 160= Rs. 176



Page No 159:

Question 10:

(c) Rs. 176

SP of an article = Rs. 144 
Loss% = 10
CP = {100(100 - Loss%)× SP} = {100(100 - 10)× 144} = 10090× 144 = 14409= Rs. 160


In order to gain 10%:

S.P. = (100 + Gain%)100× CP= (100 + 10)100× 160= 110100× 160= Rs. 176

Answer:

(a) 50%

CP of six lemons = Re 1
CP of one lemon = Rs 16

CP of four lemon = Rs 46
SP of four lemon = Re 1

 Gain =  1 - 46 =26 = Rs 13
Gain%=GainCP× 100 = 32×3× 100 = 1002=50

Page No 159:

Question 11:

(a) 50%

CP of six lemons = Re 1
CP of one lemon = Rs 16

CP of four lemon = Rs 46
SP of four lemon = Re 1

 Gain =  1 - 46 =26 = Rs 13
Gain%=GainCP× 100 = 32×3× 100 = 1002=50

Answer:

(d)Rs. 600

SP of the chair = Rs 720
Gain% = 20

C.P. = {100(100 + Profit percentage)× S.P.} ={100120× 720} = 720012 = Rs. 600

Page No 159:

Question 12:

(d)Rs. 600

SP of the chair = Rs 720
Gain% = 20

C.P. = {100(100 + Profit percentage)× S.P.} ={100120× 720} = 720012 = Rs. 600

Answer:

(c) Rs. 700

SP of a stool = Rs 630
Loss% = 10
CP = {100(100 - Loss%)× SP} ={100(100 - 10)× 630} = 10090×630 = Rs 700



Page No 160:

Question 1:

(c) Rs. 700

SP of a stool = Rs 630
Loss% = 10
CP = {100(100 - Loss%)× SP} ={100(100 - 10)× 630} = 10090×630 = Rs 700

Answer:

SP of the chair = Rs 1375
Gain% = 10

 CP of the chair={100(100 + Gain%)× SP} 

={100(100 + 10)× 1375} =137500110 = Rs. 1250

Page No 160:

Question 2:

SP of the chair = Rs 1375
Gain% = 10

 CP of the chair={100(100 + Gain%)× SP} 

={100(100 + 10)× 1375} =137500110 = Rs. 1250

Answer:

Let the cost of each pen be Rs. 1
CP of 10 pens = Rs. 10
SP of 10 pens = CP of 14 pens = Rs. 14
Gain = SP - CP = 14-10= Rs. 4
Gain% = GainCP × 100% = 410× 100%= 40%

Page No 160:

Question 3:

Let the cost of each pen be Rs. 1
CP of 10 pens = Rs. 10
SP of 10 pens = CP of 14 pens = Rs. 14
Gain = SP - CP = 14-10= Rs. 4
Gain% = GainCP × 100% = 410× 100%= 40%

Answer:

Let the cost price of the fan be Rs. x.
Gain = Rs. x10
SP of the fan = ( x + x10)= Rs. 1110x                                                                  
SP of the fan = Rs. 2585      
∴  1110x = 2585 
⇒ 11x = 25850 
⇒ x = 2585011 = 2350


So, CP of the fan is Rs. 2350.

Page No 160:

Question 4:

Let the cost price of the fan be Rs. x.
Gain = Rs. x10
SP of the fan = ( x + x10)= Rs. 1110x                                                                  
SP of the fan = Rs. 2585      
∴  1110x = 2585 
⇒ 11x = 25850 
⇒ x = 2585011 = 2350


So, CP of the fan is Rs. 2350.

Answer:

Cost price of six lemons = Rs. 10
Cost price of one lemon = Rs. 106
Cost price of eight lemons =  8 × 106 = Rs. 806 = Rs. 13.33                                         
Selling price of eight lemons = Rs. 15

  Gain = SP- CP=Rs. (15 - 13.33) = Rs. 1.67 
                                                           
Gain% = GainC.P.× 100 %
=1.6713.33× 100  %
=12.5%

Page No 160:

Question 5:

Cost price of six lemons = Rs. 10
Cost price of one lemon = Rs. 106
Cost price of eight lemons =  8 × 106 = Rs. 806 = Rs. 13.33                                         
Selling price of eight lemons = Rs. 15

  Gain = SP- CP=Rs. (15 - 13.33) = Rs. 1.67 
                                                           
Gain% = GainC.P.× 100 %
=1.6713.33× 100  %
=12.5%

Answer:

SP of the bat = Rs 486
Loss = 10%
CP of the bat = {100(100 - Loss%)× SP} 
={100(100 - 10)× 486} =  4860090 = Rs 540


CP of the bat = Rs 540

Page No 160:

Question 6:

SP of the bat = Rs 486
Loss = 10%
CP of the bat = {100(100 - Loss%)× SP} 
={100(100 - 10)× 486} =  4860090 = Rs 540


CP of the bat = Rs 540

Answer:

(b) Rs 85

SP of a football = Rs 100
Gain = Rs 15
Gain = SP - CP
        ⇒    15 = 100 - CP
       ⇒    CP = Rs (100 - 15)
       ⇒    CP= Rs 85

Page No 160:

Question 7:

(b) Rs 85

SP of a football = Rs 100
Gain = Rs 15
Gain = SP - CP
        ⇒    15 = 100 - CP
       ⇒    CP = Rs (100 - 15)
       ⇒    CP= Rs 85

Answer:

(c) 15.2%

Cost price of 12 bananas = Rs. 25
Cost price of one banana = Rs. 2512
  Cost price of five bananas=Rs. 5 × 2512 = Rs. 12512 =Rs. 10.42                                                       

He sells five bananas at the cost (SP) of Rs. 12.
Gain = SP - CP

= =Rs. (12 - 10.42) = Rs. 1.58     

 Gain% = GainCP× 100% = 1.5810.4× 100 %= 15.2%                                    

Page No 160:

Question 8:

(c) 15.2%

Cost price of 12 bananas = Rs. 25
Cost price of one banana = Rs. 2512
  Cost price of five bananas=Rs. 5 × 2512 = Rs. 12512 =Rs. 10.42                                                       

He sells five bananas at the cost (SP) of Rs. 12.
Gain = SP - CP

= =Rs. (12 - 10.42) = Rs. 1.58     

 Gain% = GainCP× 100% = 1.5810.4× 100 %= 15.2%                                    

Answer:

(c) Rs. 196

Let the cost price of the jug be Rs. x.
Loss = Rs. x7
SP of the jug = CP - Loss
=Rs. ( x - x7) = Rs. 67x                                       
                                                                                    
​SP of the jug = Rs 168         (given)

∴   67x = 168 
=168 × 76 x= 11766 x=196                    
   
∴ CP of the jug = Rs. 196

Page No 160:

Question 9:

(c) Rs. 196

Let the cost price of the jug be Rs. x.
Loss = Rs. x7
SP of the jug = CP - Loss
=Rs. ( x - x7) = Rs. 67x                                       
                                                                                    
​SP of the jug = Rs 168         (given)

∴   67x = 168 
=168 × 76 x= 11766 x=196                    
   
∴ CP of the jug = Rs. 196

Answer:

(c) 6623%

Let the cost price of each banana be Re 1.
Cost price of three bananas = Rs. 3
SP of three bananas = CP of five bananas = Rs. 5
Gain = SP - CP =  Rs. ( 5 - 3 ) = Rs. 2     
                                                        
 Gain% = GainCP× 100% = 23× 100% = 2003 %= 6623%
                                 

Page No 160:

Question 10:

(c) 6623%

Let the cost price of each banana be Re 1.
Cost price of three bananas = Rs. 3
SP of three bananas = CP of five bananas = Rs. 5
Gain = SP - CP =  Rs. ( 5 - 3 ) = Rs. 2     
                                                        
 Gain% = GainCP× 100% = 23× 100% = 2003 %= 6623%
                                 

Answer:

(i) Loss = (CP) - (SP)

(ii) CP = 100 × SP(100 + Gain%)

(iii) Profit or loss is always reckoned on the cost price.
(iv)  100 × SP(100 - loss%)  = CP

Page No 160:

Question 11:

(i) Loss = (CP) - (SP)

(ii) CP = 100 × SP(100 + Gain%)

(iii) Profit or loss is always reckoned on the cost price.
(iv)  100 × SP(100 - loss%)  = CP

Answer:

(i) False
Gain or loss is always reckoned on the cost price.
  
(ii) True
(iii) True
(iv) True



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