Rs Aggarwal 2017 Solutions for Class 7 Math Chapter 2 Fractions are provided here with simple step-by-step explanations. These solutions for Fractions are extremely popular among Class 7 students for Math Fractions Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the Rs Aggarwal 2017 Book of Class 7 Math Chapter 2 are provided here for you for free. You will also love the ad-free experience on Meritnation’s Rs Aggarwal 2017 Solutions. All Rs Aggarwal 2017 Solutions for class Class 7 Math are prepared by experts and are 100% accurate.
Page No 21:
Question 1:
Compare the fractions:
(i)
(ii)
(iii)
Answer:
We have the following:
(i)
By cross multiplication, we get:
5 12 = 60 and 7 8 = 56
However, 60 > 56
∴
(ii)
By cross multiplication, we get:
5 15 = 75 and 9 11 = 99
However, 75 < 99
∴
(iii)
By cross multiplication, we get:
11 16 = 176 and 12 15 = 180
However, 176 < 180
∴
Page No 21:
Question 2:
Arrange the following fractions in ascending order:
(i)
(ii)
Answer:
(i) The given fractions are .
LCM of 4, 6, 9 and 12 = 36
Now, let us change each of the given fractions into an equivalent fraction with 72 as its denominator.
Clearly,
Hence,
∴ The given fractions in ascending order are
(ii) The given fractions are:
LCM of 5, 10, 15 and 20 = 60
Now, let us change each of the given fractions into an equivalent fraction with 60 as its denominator.
Clearly,
Hence,
∴ The given fractions in ascending order are
Page No 22:
Question 3:
Arrange the following fractions in descending order:
(i)
(ii)
Answer:
We have the following:
(i) The given fractions are
LCM of 4,8,12 and 24 = 24
Now, let us change each of the given fractions into an equivalent fraction with 24 as its denominator.
Clearly,
Hence,
∴ The given fractions in descending order are
(ii) The given fractions are
LCM of 3,5,10 and 15 = 30
Now, let us change each of the given fractions into an equivalent fraction with 30 as its denominator.
Clearly,
Hence,
∴ The given fractions in descending order are .
Page No 22:
Question 4:
Reenu got part of an apple while Sonal got part of it. Who got the larger part and by how much?
Answer:
We will compare the given fractions in order to know who got the larger part of the apple.
We have,
By cross multiplication, we get:
2 5 = 10 and 4 7 = 28
However, 10 < 28
∴
Thus, Sonal got the larger part of the apple.
Now,
∴ Sonal got part of the apple more than Reenu.
Page No 22:
Question 5:
Find the sum:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Answer:
(i)
(ii)
[∵ LCM of 9 and 12 = 36]
=
=
(iii)
[∵ LCM of 6 and 8 = 24]
=
=
(iv)
[∵ LCM of 12, 16 and 24 = 48]
=
=
(v)
=
[∵ LCM of 5, 10 and 15 = 30]
=
=
(vi)
=
[∵ LCM of 4 and 5 = 20]
=
=
Page No 22:
Question 6:
Find the difference:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Answer:
(i)
(ii)
[∵ LCM of 6 and 4 = 12]
=
=
(iii)
=
= [∵ LCM of 5 and 10 = 10]
=
=
(iv)
=
= [∵ LCM of 1 and 3 = 3]
=
(v)
=
= [∵ LCM of 10 and 15 = 30]
=
(vi)
=
= [∵ LCM of 9 and 15 = 45]
=
Page No 22:
Question 7:
Simplify:
(i)
(ii)
(iii)
Answer:
(i)
= [∵ LCM of 3, 6 and 9 = 18]
=
(ii)
=
= [∵ LCM of 1, 2 and 4 = 4]
=
(iii)
=
= [∵ LCM of 6, 8 and 12 = 24]
=
Page No 22:
Question 8:
Aneeta bought kg apples and kg guava. What is the total weight of fruits purchased by her?
Answer:
Total weight of fruits bought by Aneeta =
Now, we have:
[∵ LCM of 2 and 4 = 4]
Hence, the total weight of the fruits purchased by Aneeta is .
Page No 22:
Question 9:
A rectangular sheet of paper is cm long and cm wide. Find its perimeter.
Answer:
We have:
Perimeter of the rectangle ABCD = AB + BC + CD +DA
=
=
= [∵ LCM of 2 and 4 = 4]
=
Hence, the perimeter of ABCD is .
Page No 22:
Question 10:
A picture is cm wide. How much should it be trimmed to fit in a frame cm wide?
Answer:
Actual width of the picture =
Required width of the picture =
∴ Extra width =
= [∵ LCM of 5 and 10 is 10]
=
Hence, the width of the picture should be trimmed by .
Page No 22:
Question 11:
What should be added to to get 18?
Answer:
Required number to be added =
=
= [∵ LCM of 1 and 5 = 5]
=
Hence, the required number is .
Page No 22:
Question 12:
What should be added to to get ?
Answer:
Required number to be added =
=
= [∵ LCM of 5 and 15 = 15]
=
Hence, the required number should be .
Page No 22:
Question 13:
A piece of wire m long broke into two pieces. One piece is m long. How long is the other piece?
Answer:
Required length of other piece of wire =
=
= [∵ LCM of 4 and 2 = 4]
=
Hence, the length of the other piece of wire is .
Page No 22:
Question 14:
A film show lasted of hours. Out of this time hours was spent on advertisements. What was the actual duration of the film?
Answer:
Actual duration of the film =
=
= [∵ LCM of 3 and 2 = 6]
=
Hence, the actual duration of the film was .
Page No 22:
Question 15:
Of and , which is greater and by how much?
Answer:
First we have to compare the fractions: .
By cross multiplication, we have:
2 9 = 18 and 5 3 = 15
However, 18 > 15
∴
So, is larger than .
Now,
= [∵ LCM of 3 and 9 = 9]
=
Hence, is part more than .
Page No 22:
Question 16:
The cost of a pen is Rs and that of a pencil is Rs . Which costs more and by how much?
Answer:
First, we have to compare the cost of the pen and the pencil.
Cost of the pen = Rs
Cost of the pencil = Rs
Now, we have to compare fractions
By cross multiplication, we get:
83 4 = 332 and 19 5 = 95
However, 332 > 95
∴
So, the cost of pen is more than that of the pencil.
Now,
= [∵ LCM of 4 and 5 = 20]
=
∴ The pen costs Rs more than the pencil.
Page No 26:
Question 1:
Find the product:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
Answer:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
(x)
(xi)
(xii)
Page No 26:
Question 2:
Simplify:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Answer:
We have the following:
(i)
(ii)
(iii)
(iv)
=
(v)
=
(vi)
=
Page No 26:
Question 3:
Find:
(i) of 24
(ii) of 32
(iii) of 45
(iv) of 1000
(v) of 1020
(vi) of Rs 220
(vii) of 54 metres
(viii) of 35 litres
(ix) of an hour
(x) of an year
(xi) of a kg
(xii) of a metre
(xiii) of a day
(xiv) of a week
(xv) of a litre
Answer:
We have the following:
(i) of 24 =
(ii) of 32 =
(iii) of 45 =
(iv) of 1000 =
(v) of 1020 =
(vi) of Rs 220 = Rs = Rs (20 5 ) = Rs 100
(vii) of 54 m = = (4 6) m = 24 m
(viii) of 35 L = = (6 5) L = 30 L
(ix) of 1 h = of 60 min = min = 10 min
(x) of an year = of 12 months = months = (2 5) months = 10 months
(xi) of a kg = of 1000 g = g = (50 7) gm = 350 g
(xii) of 1 m = of 100 cm = cm = (5 9) cm = 45 cm
(xiii) of a day = of 24 h = h = (3 7) = 21 h
(xiv) of a week = of 7 days = days = 3 days
(xv) of 1 L = of 1000 ml = ml = (20 7) ml = 140 ml
Page No 26:
Question 4:
Apples are sold at Rs per kg. What is the cost of kg of apples?
Answer:
Cost of 1kg of apples =
∴ Cost of of apples =
=
Hence, the cost of of apples is Rs 69.
Page No 26:
Question 5:
Cloth is being sold at Rs per metre. What is the cost of metres of this cloth?
Answer:
Cost of 1 m of cloth =
∴ Cost of of cloth = Rs
= Rs
Hence, the cost of of cloth is Rs 238.
Page No 26:
Question 6:
A car covers a certain distance at a uniform speed of km per hour. How much distance will it cover in 9 hours?
Answer:
Distance covered by the car in 1 h =
Distance covered by the car in 9 h =
=
Hence, the distance covered by the car in 9 h will be 600 km.
Page No 26:
Question 7:
One tin holds litres of oil. How many litres of oil can 26 such tins hold?
Answer:
Capacity of 1 tin =
∴ Capacity of 26 such tins =
=
Hence, 26 such tins can hold L of oil.
Page No 26:
Question 8:
For a particular show in a circus, each ticket costs Rs . If 308 tickets are sold for the show, how much amount has been collected?
Answer:
Cost of 1 ticket = Rs = Rs
∴ Cost of 308 tickets = Rs
Hence, 308 tickets were sold for Rs 10,934.
Page No 26:
Question 9:
Nine boards are stacked on the top of each other. The thickness of each board is cm. How high is the stack?
Answer:
Thickness of 1 board = cm
∴ Thickness of 9 boards =
= = (3 11) cm = 33 cm
Hence, the height of the stack is 33 cm.
Page No 27:
Question 10:
Rohit takes minutes to make complete round of a circular park. How much time will he take to make 15 rounds?
Answer:
Time taken by Rohit to complete one round of the circular park = min = min
∴ Time taken to complete 15 rounds = min
= (3 24) min
= 72 min
= 1 h 12 min [∵ 1 hr = 60 min]
Hence, Rohit will take 1 h 12 min to make 15 complete rounds of the circular park.
Page No 27:
Question 11:
Amit weighs 35 kg. His sister Kavita's weight is of Amit's weight. How much does Kavita weigh?
Answer:
Weight of Amit = 35 kg
Weight of Kavita = of Amit's weight
= 35 kg x =
Hence, Kavita's weight is 21 kg.
Page No 27:
Question 12:
There are 42 students in a class and of the students are boys. How many girls are there in the class?
Answer:
Number of boys in the class = of the total no. of students
= 42 =
∴ Number of girls in the class = 42 − 30 = 12
Hence, there are 12 girls in the class.
Page No 27:
Question 13:
Sapna earns Rs 12000 per month. She spends of her income and deposits rest of the money in a bank. How much money does she deposit in the bank each month?
Answer:
Sapna's total monthly income = Rs 12000
Monthly expenditure = of Rs 12000
= Rs =Rs (7 1500) = Rs 10500
∴ Monthly savings = Rs 12000 − Rs 10500
= Rs 1500
Hence, Sapna deposits Rs 1500 in the bank every month.
Page No 27:
Question 14:
Each side of a square field is m. Find its area.
Answer:
Side of the square field =
∴ Area of the square = (side)2
=
=
Hence, the area of the square field is .
Page No 27:
Question 15:
Find the area of a rectangular park which is m long and m broad.
Answer:
Length of the rectangular park =
Its breadth =
∴ Its area = length breadth
= 2
= (25 31) m = 775 m2
Hence, the area of the rectangular park is 775 m2.
Page No 30:
Question 1:
Write down the reciprocal of:
(i)
(ii) 7
(iii)
(iv)
Answer:
(i) Reciprocal of = [ ∵ ]
(ii) Reciprocal of 7 = [ ∵ ]
(iii) Reciprocal of = 12 [ ∵ ]
(iv) Reciprocal of = Reciprocal of = [∵ ]
Page No 30:
Question 2:
Simplify:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
(vii)
(viii)
(ix)
Answer:
(i) [∵ Reciprocal of = ]
=
(ii) [∵ Reciprocal of = ]
=
(iii) [∵ Reciprocal of 16 = ]
=
(iv) [∵ Reciprocal of = 3]
= 27
(v) [∵ Reciprocal of = ]
= 4 7 = 28
(vi)
= [∵ Reciprocal of = ]
=
(vii)
= [∵ Reciprocal of = ]
= 3 3 = 9
(viii) =
= [∵ Reciprocal of = ]
=
(ix) =
= [∵ Reciprocal of = ]
=
Page No 30:
Question 3:
Divide:
(i)
(ii)
(iii)
(iv)
(v)
(vi)
Answer:
(i)
= [∵ Reciprocal of = ]
=
(ii) =
= [∵ Reciprocal of = ]
= 5 2 = 10
(iii) =
= [∵ Reciprocal of = ]
= =
(iv) =
= [∵ Reciprocal of = ]
= 4 5 = 20
(v) =
= [∵ Reciprocal of = ]
= 5 5 = 25
(vi) =
= [∵ Reciprocal of = ]
= 7 4 = 28
Page No 30:
Question 4:
A rope of length m has been divided into 9 pieces of the same length. What is the length of each piece?
Answer:
Length of the rope = m = m
Number of equal pieces = 9
∴ Length of each piece = m
= m [∵ Reciprocal of 9 = ]
= m = m
Hence, the length of each piece of rope is m.
Page No 30:
Question 5:
18 boxes of nails weigh equally and their total weight is kg. How much does each box weigh?
Answer:
Weight of 18 boxes of nails = kg = kg
∴ Weight of 1 box = kg
= kg [∵ Reciprocal of 18 = ]
= kg = kg = kg = kg
Hence, the weight of each box is kg.
Page No 31:
Question 6:
By selling oranges at the rate of Rs per orange, a man gets Rs 210. How many oranges does he sell?
Answer:
Cost of 1 orange = Rs = Rs
Total cost of the oranges sold by the man = Rs 210
∴ Required number of oranges =
= [∵ Reciprocal of = ]
= (14 4) = 56
Hence, the man sold 56 oranges.
Page No 31:
Question 7:
Mangoes are sold at Rs per kg. What is the weight of mangoes available for Rs ?
Answer:
Cost of 1 kg of mangoes = Rs = Rs
Total cost of the required mangoes = Rs = Rs
∴ Weight of the required mangoes = kg
= kg [∵ Reciprocal of = ]
= kg = kg
Hence, the weight of the mangoes available for Rs is kg.
Page No 31:
Question 8:
Vikas can cover a distance of km in hours on foot. How many km per hour does he walk?
Answer:
Distance covered by Vikas in h = km
∴ Distance covered by him in 1 h = km
= km
= km
= km = km = km
Hence, the distance covered by Vikas in 1 h is km.
Page No 31:
Question 9:
Preeti bought kg of sugar for Rs . Find the price of sugar per kg.
Answer:
Cost of kg of sugar = Rs
∴ Cost of 1 kg of sugar = Rs
= Rs
= Rs = Rs = Rs
Hence, the cost of 1 kg of sugar is Rs .
Page No 31:
Question 10:
If the cost of a notebook is Rs , how many notebooks can be purchased for Rs ?
Answer:
Cost of 1 notebook = Rs = Rs
∴ Number of notebooks purchased for Rs =
=
= [∵ Reciprocal of =]
= = 9
Hence, 9 notebooks can be purchased for Rs .
Page No 31:
Question 11:
At a charity show the price of each ticket was Rs . The total amount collected by a boy was Rs . How many tickets were sold by him?
Answer:
Cost of 1 ticket = Rs = Rs
Total amount collected by the boy = Rs = Rs
∴ Number of tickets sold =
= [∵ Reciprocal of = ]
=
Hence, the boy sold 27 tickets of the charity show.
Page No 31:
Question 12:
A group of students arranged a picnic. Each student contributed Rs . The total contribution was Rs . How many students are there in the group?
Answer:
Amount contributed by 1 student = Rs = Rs
Total amount collected = Rs = Rs
∴ Number of students in the group =
= [∵ Reciprocal of = ]
=
Hence, there are 11 students in the group.
Page No 31:
Question 13:
24 litres of milk was distributed equally among all the students of a hostel. If each student got litre of milk, how many students are there in the hostel?
Answer:
Quantity of milk given to each student = L
Total quantity of milk distributed among all the students = 24 L
∴ Number of students =
= [∵ Reciprocal of = ]
= (12 5) = 60
Hence, there are 60 students in the hostel.
Page No 31:
Question 14:
A bucket contains litres of water. A small jug has a capacity of litre. How many times the jug has to be filled with water from the bucket to get it emptied?
Answer:
Capacity of the small jug = L
Capacity of the bucket = L = L
∴ Required number of small jugs =
= [∵ Reciprocal of = ]
= = 27
Hence, the small jug has to be filled 27 times to empty the water from the bucket.
Page No 31:
Question 15:
The product of two numbers is . If one of the numbers is , find the other.
Answer:
Product of the two numbers = =
One of the numbers = =
∴ The other number =
= [∵ Reciprocal of = ]
=
Hence, the other number is .
Page No 31:
Question 16:
By what number should be multiplied to get 42?
Answer:
Product of the two numbers = 42
One of the numbers = =
∴ The other number =
= [∵ Reciprocal of = ]
=
Hence, the required number is .
Page No 31:
Question 17:
By what number should be divided to obtain ?
Answer:
Required number =
=
= [ ∵ Reciprocal of = ]
=
Hence, we have to divide by to get .
Page No 31:
Question 1:
Mark (✓) against the correct answer
Which of the following is a vulgar fraction?
(a)
(b)
(c)
(d) none of these
Answer:
(c)
is a vulgar fraction, because its denominator is other than 10, 100, 1000, etc.
Page No 31:
Question 2:
Mark (✓) against the correct answer
Which of the following is an improper fraction?
(a)
(b)
(c)
(d) none of these
Answer:
(c)
is an improper fraction, because its numerator is greater than its denominator.
Page No 31:
Question 3:
Mark (✓) against the correct answer
Which of the following is a reducible fraction?
(a)
(b)
(c)
(d)
Answer:
(a)
A fraction that is reducible can be reduced by dividing both the numerator and denominator by a common factor.
Thus, is a reducible fraction.
Page No 32:
Question 4:
Mark (✓) against the correct answer
are
(a) like fractions
(b) irreducible fractions
(c) equivalent fractions
(d) none of these
Answer:
(c) equivalent fractions
Equivalent fractions are those which are the same but look different.
Thus, are equivalent fractions.
Page No 32:
Question 5:
Mark (✓) against the correct answer
Which of the following statements is true?
(a)
(b)
(c)
(d) none of these
Answer:
(c) >
The two fraction are and .
By cross multiplication, we have:
9 24 = 216 and 13 16 = 208
However, 216 > 208
∴ >
Page No 32:
Question 6:
Mark (✓) against the correct answer
Reciprocal of is
(a)
(b)
(c)
(d) none of these
Answer:
(d) none of these
Reciprocal of = Reciprocal of =
Page No 32:
Question 7:
Mark (✓) against the correct answer
(a)
(b)
(c)
(d) none of these
Answer:
(c)
[∵ LCM of 10 and 15 = 30]
=
Page No 32:
Question 8:
Mark (✓) against the correct answer
(a)
(b)
(c)
(d)
Answer:
(d)
=
= [∵ LCM of 4 and 3 = 12]
=
Page No 32:
Question 9:
Mark (✓) against the correct answer
(a) 9
(b)
(c)
(d) 144
Answer:
(d) 144
[∵ Reciprocal of = 4]
= 144
Page No 32:
Question 10:
Mark (✓) against the correct answer
By what number should be multiplied to get ?
(a)
(b)
(c)
(d)
Answer:
(b)
Required number =
=
= [∵ Reciprocal of = ]
=
Page No 32:
Question 11:
Mark (✓) against the correct answer
By what number should be divided to get ?
(a)
(b)
(c)
(d)
Answer:
(d)
Required number =
=
= [∵ Reciprocal of = ]
=
Page No 32:
Question 12:
Mark (✓) against the correct answer
(a)
(b)
(c)
(d) none of these
Answer:
(c)
= [∵ Reciprocal of = ]
=
Page No 32:
Question 13:
Mark (✓) against the correct answer
(a) 1
(b) 2
(c)
(d)
Answer:
(d)
= [∵ Reciprocal of = ]
=
Page No 32:
Question 14:
Mark (✓) against the correct answer
The reciprocal of is
(a)
(b)
(c)
(d)
Answer:
(d)
Reciprocal of = Reciprocal of =
Page No 32:
Question 15:
Mark (✓) against the correct answer
Which one of the following is the correct statement?
(a)
(b)
(c)
(d) none of these
Answer:
(b)
The given fractions are
LCM of 5, 3 and 15 = 15
Now, we have:
, and
Clearly,
∴
Page No 33:
Question 16:
Mark (✓) against the correct answer
A car runs 16 km using 1 litre of petrol. How much distance will it cover in litres of petrol?
(a) 24 km
(b) 36 km
(c) 44 km
(d) km
Answer:
(c) 44 km
Distance covered by the car on L of petrol = km
= km
= (4 11) km = 44 km
Page No 33:
Question 17:
Mark (✓) against the correct answer
Lalit reads a book for hours evrey day and reads the entire book in 6 days. How many hours does he take to read the entire book?
(a) hours
(b) hours
(c) hours
(d) hours
Answer:
(a) hours
Time taken by Lalit to read the entire book = h
= h
= h = h
Page No 34:
Question 1:
Define:
(i) Fractions
(ii) Vulgar fractions
(iii) Improper fractions
Give two examples of each.
Answer:
(i) A number of the form , where a and b are natural numbers, is called a natural number.
Here, a is the numerator and b is the denominator.
is a fraction with 2 as the numerator and 3 as the denominator.
is a fraction with 12 as the numerator and 5 as the denominator.
(ii) A fraction whose denominator is a whole number other than 10, 100, 1000, etc., is called a vulgar faction.
Examples: and
(iii) A fraction whose numerator is greater than or equal to its denominator is called an improper fraction.
Examples: and
Page No 34:
Question 2:
What should be added to to get 15?
Answer:
Required number to be added =
=
= [∵ LCM of 1 and 5 = 5]
=
Hence, the required number is .
Page No 34:
Question 3:
Simplify:
Answer:
We have,
=
= [∵ LCM of 6, 8 and 12 = 24]
= =
Page No 34:
Question 4:
Find:
(i) of a litre
(ii) of a kilogram
(iii) of an hour
Answer:
We have:
(i) of 1 L = of 1000 ml = ml = (40 12) ml = 480 ml
(ii) of 1 kg = of 1000 g = g = (125 5) g = 625 g
(iii) of 1 h = of 60 min = min = (12 3) min = 36 min
Page No 34:
Question 5:
Milk is sold at Rs per litre. Find the cost of litres milk.
Answer:
Cost of 1 L of milk = Rs = Rs
Cost of L of milk = Rs
= Rs
= Rs = Rs = Rs
Hence, the cost of L of milk is Rs .
Page No 34:
Question 6:
The cost of kg of mangoes is Rs 189. At what rate per kg are the mangoes being sold?
Answer:
Cost of kg of mangoes = Rs 189
Cost of 1 kg of mango = Rs
= Rs
= Rs [∵ Reciprocal of = ]
= Rs (9 4) = Rs 36
Hence, the mangoes are being sold at Rs 36 per kg.
Page No 34:
Question 7:
Simplify:
(i)
(ii)
Answer:
We have:
(i)
=
=
(ii)
=
= [∵ Reciprocal of = ]
=
Page No 34:
Question 8:
By what number should be divided to obtain ?
Answer:
Required number =
=
= [∵ Reciprocal of = ]
= =
Hence, we have to divide by to obtain .
Page No 34:
Question 9:
Each side of a square is m long. Find its area.
Answer:
Side of the square = m = m
Its area = (side)2 = =
Hence, the area of the square is .
Page No 34:
Question 10:
Mark (✓) against the correct answer
Which of the following is a vulgar fraction?
(a)
(b)
(c)
(d)
Answer:
(d)
is a vulgar fraction, because its denominator is other than 10, 100, 1000, etc.
Page No 34:
Question 11:
Mark (✓) against the correct answer
Which of the following is an irreducible fraction?
(a)
(b)
(c)
(d)
Answer:
(c)
A fraction is said to be irreducible or in its lowest terms if the HCF of a and b is 1.
46 = 2 23 1
63 = 3 3 21 1
Clearly, the HCF of 46 and 63 is 1.
Hence, is an irreducible fraction.
Page No 34:
Question 12:
Mark (✓) against the correct answer
Reciprocal of is
(a)
(b)
(c)
(d) none of these
Answer:
(d) none of these
Reciprocal of = Reciprocal of =
Page No 34:
Question 13:
Mark (✓) against the correct answer
(a)
(b)
(c)
(d) none of these
Answer:
(c)
=
= [∵ Reciprocal of = ]
=
Page No 34:
Question 14:
Mark (✓) against the correct answer
Which of the following is correct?
(a)
(b)
(c)
(d)
Answer:
(b)
The given fractions are and .
LCM of 5, 3 and 15 = 15
Now, we have:
, and
Clearly,
∴
Page No 34:
Question 15:
Mark (✓) against the correct answer
By what number should be divided to get ?
(a)
(b)
(c)
(d)
Answer:
(c)
Required number =
=
= [∵ Reciprocal of = ]
=
Page No 35:
Question 16:
Mark (✓) against the correct answer
A car runs 9 km using 1 litre of petrol. How much distance will it cover in litres o petrol?
(a) 36 km
(b) 33 km
(c) km
(d) 22 km
Answer:
(b) 33 km
Distance covered by the car on L of petrol = km
= km
= (3 11) km = 33 km
Page No 35:
Question 17:
Fill in the blanks.
(i) Reciprocal of is ...... .
(ii)
(iii)
(iv)
(v) (in irreducible form)= ......
Answer:
(i) The reciprocal of is .
Reciprocal of = Reciprocal of =
(ii)
(iii)
= = 9
(iv)
=
(v) (irreducible form) =
The HCF of 84 and 98 is 14.
∴
Page No 35:
Question 18:
Write 'T' for true and 'F' for false
(i)
(ii) Among and , the largest is
(iii)
(iv) of a litre = 440 mL.
(v)
Answer:
(i) F
By cross multiplication, we have:
9 24 = 216 and 13 16 = 208
However, 216 > 208
∴
(ii) F
The LCM of 5, 35 and 14 is 70.
Now,
Clearly,
∴
(iii) T
The LCM of 15 and 20 = (5 3 4) = 60
∴
(iv) T
of 1 L = of 1000 ml = ml = (40 11) ml = 440 ml
(v) F
=
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