Page 114 - ICSE Math 8

5 Ê 5 ˆ 5x
⇒ C.P. of 1 button = ` ⇒ C.P. of x buttons = ` Á ¥ x = `
˜
3 Ë 3 ¯ 3
12
S.P. of 5 buttons = ` 12 ⇒ S.P. of 1 button = `
5
Ê 12 ˆ 12x
⇒ S.P. of x buttons = ` Á 5 ¥ x = ` 5
˜
¯
Ë
Since she had a profit,
12x 5x Ê 36x - 25xˆ 11x
∴ Profit = ` – ` = ` Á ˜ = `
5 3 Ë 15 ¯ 15
Profit given = ` 143
11x 143 15×
⇒ = 143 ⇒ x = = 195
15 11
Hence, Anuradha purchased 195 buttons.

EXERCISE 10.1

1. Prachi bought a bangle box for ` 350. She sold it for ` 425. Find her profit per cent.
2. Heena lost ` 15 by selling a saree for ` 500. Find the loss per cent.
3. A merchant bought 10 kg of rice at ` 70 per kg. He sold 5 kg at ` 100 per kg and the remaining at
` 80 per kg. Find his profit and the profit per cent.
4. The selling price of 10 books is equal to the cost price of 12 books. Find the profit per cent.
5. A fruit seller buys mangoes at ` 350 per hundred and sells them at ` 48 per dozen. Find his profit or loss
per cent.
6. Rajesh bought a sofa set for ` 6,500 and paid ` 150 for its transportation. He then sold it for ` 7,500. Find
his profit per cent.
7. Sonika sells two jewellery boxes for ` 1,400 each. On one she earns a profit of 10% and on the other she
incurs a loss of 10%. Find her overall profit or loss per cent.
8. Aditya and Manav purchased one scooter each for the same price. Aditya sold it for ` 18,400 and lost 8%.
At what price should Manav sell it to have a profit of 6%?
9. A shopkeeper bought 30 cricket balls at the rate of ` 40 per ball. He sold 20 balls at the rate of ` 50 per
ball. At what rate should he sell the remaining balls to have a profit of 40% in the whole transaction?
1
10. A shopkeeper sold a wrist watch for ` 990 gaining of its cost price. Find the cost price of the wrist
watch and his profit per cent. 8

Discount

In the market, the price of every article is marked. The printed price or the tagged price of an article is called
its marked price (M.P.). However, you must have noticed bumper sale advertisements. In such sales, to
clear the stocks or for other reasons, the seller sells the goods at prices lower than the normal marked price.
The deduction or rebate allowed on the marked price is called discount.
So the buyer pays the difference between M.P. and discount.

Discount
S.P. = M.P. – Discount Discount % = ×100
M.P.
Ê 100 - Discount% ˆ 100 ¥S.P.
S.P. = Á 100 ˜ ¯ ¥ M.P. M.P. = ( 100 - Discount%)
Ë

102