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# RD Sharma (2014) Solutions for Class 7 Math Chapter 10 - Unitary Method

RD Sharma (2014) Solutions for Class 7 Math Chapter 10 Unitary Method are provided here with simple step-by-step explanations. These solutions for Unitary Method are extremely popular among class 7 students for Math Unitary Method Solutions come handy for quickly completing your homework and preparing for exams. All questions and answers from the RD Sharma (2014) Book of class 7 Math Chapter 10 are provided here for you for free. You will also love the ad-free experience on Meritnation’s RD Sharma (2014) Solutions. All RD Sharma (2014) Solutions for class 7 Math are prepared by experts and are 100% accurate.

#### Question 1:

20 chocolates cost Rs 320. Find the cost of 35 such chocolates.

Cost of 20 chocolates  = Rs. 320
Cost of 1 chocolate    =  Rs. 320 ÷ 20 =  16
So, cost of 35 chocolates = 35  ×  16 = Rs. 560

#### Question 2:

The cost of 40 metres of cloth is Rs 200. Find the cost of 50 metres of cloth.

Cost of 40 metres of cloth = Rs. 200
Therefore, cost of 1 metre of cloth = Rs.
Hence, cost of 50 metres of cloth = Rs. 5(50) = Rs. 250

#### Question 3:

A car can cover a distance of 522 km on 36 litres of petrol. How far can it travel on 14 litres of petrol?

Distance covered by the car on 36 litres  = 522 km
Distance covered by the car on 1 litre = 522 ÷ 36
Distance covered by the car on 14 litres = (522 ÷ 36) × 14  = 203 km

#### Question 4:

Travelling 900 km by rail costs Rs 280. What would be the fare for a journey of 360 km when a person travels by the same class?

Fare for 900 km of rail travel = Rs. 280
Fare for 1 km =  Rs. 280 ÷  900
Therefore, fare for 360 km = (280 ÷ 900) × 360 =  Rs. 112

#### Question 5:

If 6 oil tankers can be filled by a pipe in 4 $1}{2}$ hours, how long does the pipe take to fill 4 such oil tankers?

Time taken by the pipe to fill 6 oil tankers = 4 1/2 = 9/2 hours
Time taken to fill 1 oil tanker =
Therefore, the pipe will be able to fill 4 oil tankers in

#### Question 6:

3/4 of the salary per month is Rs 600. What is the salary per month?

Let the salary be Rs. x.
Then, 3/4 of the salary per month = Rs. 600.
That is, (3/4) x = 600
⇒ = (4​ × 600) ÷ 3 = Rs. 800
So, the salary = Rs. 800.

#### Question 7:

The cost of 32 tables is Rs 23520. Find the number of such tables that can be purchased for Rs 51450.

With Rs. 23520, we can buy 32 tables.
Therefore, with Re. 1, we can buy tables.
Hence, the number of tables that we can purchase with Rs. 51450 = $\frac{2}{23520}×51450$ = 70.

#### Question 8:

The yield of wheat from 6 hectares is 280 quintals. Find the number of hectares required for a yield of 225 quntals.

Yield of wheat from 6 hectares = 280 quintals
Yield of wheat from 1 hectare = 280 ÷ 6 =  46.66 quintals
Number of hectares required for a yield of 225 quintals = 225 ÷ 46.66 = 4.8 hectares
So, 4.8 hectares is required for a yield of 225 quintals.

#### Question 9:

Fifteen post cards cost Rs 2.25. What will be the cost of 36 post cards? How many postcards can we buy in Rs 45?

Cost of 15 postcards = Rs. 2.25
Cost of 1 postcard = Rs. 2.25 ​÷ 15  =  Rs. 0.15
Cost of 36 postcards = 36 × (2.25 ÷ 15) =  Rs. 5.4
Number of postcards that can be bought for Rs. 45 = 45 ​÷ 0.15 = 300

#### Question 10:

A rail journey of 75 km costs Rs 215. How much will a journey of 120 km cost?

Fare for a rail journey of 75 km = Rs. 215
Fare for 1 km = Rs. 215 ÷ 75 =  Rs. 2.86
Fare for 120 km = Rs. 120  × 2.86 = Rs. 343.2

#### Question 11:

If the sales tax on a purchase wirth Rs 60 is Rs 4.20. What will be the sales tax on the purchase worth of Rs 150?

Sales tax on purchase worth Rs. 60 = Rs. 4.20
Sales tax on purchase worth Re. 1 = 4.20 ÷  60
Therefore, sales tax on purchase worth Rs. 150 = Rs. 150 × (4.20 ÷ 60) = Rs. 10.5.

#### Question 12:

52 packets of 12 pencils each, cost Rs 499.20. Find the cost of 65 packets of 10 pencils each.

Cost of 52 packets of 12 pencils each = Rs. 499.20
Cost of 1 packet of 12 pencils = Rs. 499.20 ​÷ 52 = Rs. 9.6
Therefore, cost of 12 pencils = Rs. 9.6
So, cost of 1 pencil = Rs. 9.6 ÷ 12 = Rs. 0.8
Cost of 10 pencils = Rs. 10 × (9.6 ​÷ 12) = Rs. 8
Therefore, cost of 1 packet of 10 pencils each = Rs. 8
Hence, cost of 65 packets of 10 pencils each =  65  × Rs. 8 = Rs. 520

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