# EXERCISE 8.3

QUESTION 1

**Tell what is the profit or loss in the following transactions. Also find profit percent or loss percent in each case.**

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

Sol :

(a) Cost price = Rs 250

Selling price = Rs 325

Profit = 325 — 250 = Rs 75

= 30%

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

Sol :

(b) Cost price = Rs 12000

Selling price = Rs 13,500

Profit : 13500 — 12000 = Rs 1500

= 12.5 %

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

Sol :

(c) Cost price = Rs 2500

Selling price = Rs 3000

Profit = 3000 — 2500 = Rs 500

= 20 %

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

Sol :

(d) Cost price = Rs 250

Selling price = Rs 150

Loss = 250—150=Rs 100

= 40 %

QUESTION 2

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

**(a) 3:1**

Sol :

Total parts = 3 + 1 = 4

1^{st} part

= 75 %

2^{nd} part

= 25 %

**(b) 2:3:5**

Sol :

Total parts = 2 + 3 + 5 = 10

1^{st} part

= 20 %

2^{nd} part

= 30 %

3^{nd} part

= 50 %

**(c) 1:4**

Sol :

Total parts = 1 + 4 = 5

1^{st} part

= 20 %

2^{nd} part

= 80 %

**(d) 1:2:5**

Sol :

Total parts = 1 + 2 + 5 = 8

1^{st} part

= 12.5 %

2^{nd} part

= 25 %

3^{nd} part

= 62.5 %

QUESTION 3

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

Sol :

Initial population = 25000

Final population = 24500

Decrease = 500

= 2 %

QUESTION 4

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

Sol :

Initial price = Rs 350000

Final price = Rs 370000

Increase = Rs 20000

QUESTION 5

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

Sol :

Cost price = Rs 10000

Profit = 20% of 10000

= 2000

Selling price = Cost price + Profit

S.P = 10000 + 2000 = Rs 12,000

QUESTION 6

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

Sol :

Selling price = Rs 13500

Loss % = 20%

Let the cost price be x.

∴ Loss = 20% of x

Cost price — Loss = Selling price

= 16875

Therefore, she bought it for Rs 16875

QUESTION 7

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

Sol :

(i) Ratio of calcium, carbon, and oxygen = 10 : 3 : 12

As 10 + 3 + 12 = 25 ,

Therefore , the percentage of the carbon

= 12 %

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

Sol :

(ii) Let the weight of the stick be x g.

12 % of x = 3

= 25 g

QUESTION 8

**Amina buys a book for Rs 275 and sells it at a loss of 1 5%. How much does she sell it for?**

Sol :

Cost price = Rs 275

Loss % = 15 %

Loss = 15% of 275

Cost price — Loss = Selling price

275 – 41.25 = Selling Price

Selling Price = 233.75

QUESTION 9

**Find the amount to be paid at the end of 3 years in each case:**

**(a) Principal = Rs 1,200 at 12% pa.**

Sol :

(a) Principal (P) = Rs 1200

Rate (R) =12 % p.a.

Time (T) = 3 years

= 432

Amount = P + S.I.

= 1200 + 432

= Rs 1632

**(b) Principal = Rs 7,500 at 5% pa.**

Sol :

(b) P = Rs 7500

R = 5 % p.a

T = 3 years

= Rs 1125

Amount = 3500 +1125

= Rs 8625

QUESTION 10

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

Sol :

R = 0.25

Therefore, 0.25% gives Rs 280 as interest on the given sum.

QUESTION 11

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

Sol :

= Rs 500

Therefore, she borrowed Rs 500