**NCERT Solutions for Class 7 Maths Chapter 7 Comparing Quantities Ex 7.1****NCERT Solutions for Class 7 Maths Chapter 7 Comparing Quantities Ex 7.2**

**NCERT Solutions for Class 7 Maths Chapter 7 ****Comparing Quantities**** Ex 7.2 ****(Rationalised Contents)**

**Ex 7.2 Class 7 Maths Question 1.**

### Tell what is the profit or loss in the following transactions. Also find profit per cent or loss per cent in each case.

(a) Gardening shears bought for ₹ 250 and sold for ₹ 325.

(b) A refrigerator bought for ₹ 12,000 and sold at ₹ 13,500.

(c) A cupboard bought for ₹ 2,500 and sold at ₹ 3,000.

(d) A skirt bought for ₹ 250 and sold at ₹ 150.

**Solution:**(a) Here, CP = ₹ 250 and SP = ₹ 325

Since, SP > CP, there is a profit.

∴ Profit = SP – CP

= ₹ 325 – ₹ 250 = ₹ 75

Hence, the required profit is ₹ 75 and profit per cent is 30%.

(b) Here, CP = ₹ 12,000 and SP = ₹ 13,500

Since, SP > CP, there is a profit.

∴ Profit = SP – CP

= ₹ 13,500 – ₹ 12,000 = ₹ 1,500

Hence, the required profit is ₹ 1500 and profit per cent is 12^{1}/_{2}%.

(c) Here, CP = ₹ 2500 and SP = ₹ 3000

Since, SP > CP, there is a profit.

∴ Profit = SP – CP

= ₹ 3000 – ₹ 2500 = ₹ 500

Hence, the required profit is ₹ 500 and profit per cent is 20%.

(d) Here, CP = ₹ 250 and SP = ₹ 150

Since, SP < CP, there is a loss.

∴ Loss = CP – SP

= ₹ 250 – ₹ 150 = ₹ 100

Hence, the required loss is ₹ 100 and loss per cent is 40%.

**Ex ****7.2**** Class 7 Maths Question 2.**

### Convert each part of the ratio to percentage:

(a) 3 : 1

(b) 2 : 3 : 5

(c) 1 : 4

(d) 1 : 2 : 5

**Solution:**(a) 3 : 1

Sum of the ratio parts = 3 + 1 = 4

(b) 2 : 3 : 5

Sum of the ratio parts = 2 + 3 + 5 = 10

(c) 1 : 4

Sum of the ratio parts = 1 + 4 = 5

(d) 1 : 2 : 5

Sum of the ratio parts = 1 + 2 + 5 = 8

**Ex ****7.2**** Class 7 Maths Question 3.**

### The population of a city decreased from 25,000 to 24,500. Find the percentage decrease.

**Solution:**Initial population of the city = 25,000

Decreased population of city = 24,500

Decrease in population = 25,000 – 24,500 = 500

Percentage decrease = (500 × 100)/25000 = 2%

Hence, the percentage decrease in population of the city is 2%.

**Ex ****7.2**** Class 7 Maths Question 4.**

### Arun bought a car for ₹ 3,50,000. The next year, the price went up to ₹ 3,70,000. What was the percentage of price increase?

**Solution:**Original price of the car = ₹ 3,50,000

Increased price of the car = ₹ 3,70,000

Increase in price = ₹ 3,70,000 – ₹ 3,50,000

= ₹ 20,000

∴ Percentage increase

^{5}/

_{7 }%.

**Ex ****7.2**** Class 7 Maths Question 5.**

### I buy a TV for ₹ 10,000 and sell it at a profit of 20%. How much money do I get for it?

**Solution:**Here, CP = ₹ 10,000

^{ }and Profit = 20%

SP = ?

Hence, the money got by me for the TV is ₹ 12,000.

** **

**Ex ****7.2**** Class 7 Maths Question 6.**

### Juhi sells a washing machine for ₹ 13,500. She loses 20% in the bargain. What was the price at which she bought it?

**Solution:**Here, Selling price of the washing machine = ₹ 13,500

Loss = 20%

CP = ?

Hence, the cost price of the washing machine is ₹ 16,875.

**Ex ****7.2**** Class 7 Maths Question 7.**

### (i) Chalk contains calcium, carbon and oxygen in the ratio 10 : 3 : 12. Find the percentage of carbon in chalk.

(ii) If in a stick of chalk, carbon is 3 g, what is the weight of the chalk stick?

**Solution:**(i) Sum of the ratio parts = 10 + 3 + 12 = 25

∴ Percentage of carbon in chalk

= (3/25) × 100% = 12%

Hence, the percentage of carbon in chalk is 12%.

(ii) Weight of carbon = 3 g

If carbon part in chalk stick is 3, the total part is 25.

If carbon weight is 3 g, the total weight of the chalk stick = (3 × 25)/3 g = 25 g

Hence, the weight of chalk stick is 25 g.

**Ex ****7.2**** Class 7 Maths Question 8.**

### Amina buys a book for ₹ 275 and sells it at a loss of 15%. How much does she sell it for?

**Solution:**Here, CP of the book = ₹ 275 and Loss = 15%

**Ex ****7.2**** Class 7 Maths Question 9.**

### Find the amount to be paid at the end of 3 years in each case.

(a) Principal = ₹ 1200 at 12% p.a.

(b) Principal = ₹ 7500 at 5% p.a.

**Solution:**(a) Given: Principal (P) = ₹ 1200

Rate of interest (R) = 12% p.a., T = 3 years

∴ Simple Interest = (P × R × T)/100 = (1200 × 12 × 3)/100 = ₹432

Amount = Principal + Interest

= ₹ 1200 + ₹ 432 = ₹ 1632

Hence, the required amount is ₹ 1632.

(b) Given: Principal (P) = ₹ 7500

Rate of interest (R) = 5% p.a., T = 3 years

∴ Simple Interest = (P × R × T)/100 = (7500 × 5 × 3)/100 = ₹1125

Amount = Principal + Interest

= ₹ 7500 + 1125 = ₹ 8625

Hence, the required amount is ₹ 8625.

**Ex ****7.2**** Class 7 Maths Question 10.**

### What rate gives ₹ 280 as interest on a sum of ₹ 56,000 in 2 years?

**Solution:**Given: Principal (P) = ₹ 56,000

Interest (I) = ₹280 and Time = 2 years

Rate of interest (R) = ?

**Ex ****7.2**** Class 7 Maths Question 11.**

### If Meena gives an interest of ₹ 45 for one year at 9% rate p.a. What is the sum she has borrowed?

**Solution:**Given: Interest (I) = ₹45

Time (T) = 1 year

Rate of interest (R) = 9% p.a.

**Related Links:**

**NCERT Solutions for Maths Class 8**

**NCERT Solutions for Maths Class 9**

**NCERT Solutions for Maths Class 10**