Page 117 - ICSE Math 8

Example 13: The marked price of a blanket is ` 1,000. After two successive discounts it is sold for ` 630.
If the first discount is 30%, what is the rate of the second discount?
Solution: M.P. of a blanket = ` 1,000; First discount (D %) = 30%; S.P. of blanket = ` 630
1
Let the second discount be D %.
2
Ê 100 - D % ˆ Ê 100 - D % ˆ
S.P. = Á Ë 100 1 ˜ Á 100 2 ˜ × M.P.
¯ Ë
¯
Ê 100 30- ˆ Ê 100 - D % ˆ Ê 70 ˆ Ê 100 - D % ˆ
⇒ 630 = Á Ë 100 ˜ Á 100 2 ˜ × 1,000 = Á Ë 100¯ Ë 100 2 ˜ ¥ ,
1 000
˜ Á
¯
¯
¯ Ë
630 100 100× ×
⇒ 100 – D % = ⇒ 100 – D % = 90 ⇒ D % = 100 – 90 = 10%
2
2
2
70 1 000× ,
Hence, the rate of the second discount is 10%.
EXERCISE 10.2
1. Find the S.P., if
(a) M.P. = ` 320 and Discount % = 12.5% (b) M.P. = ` 990 and Discount % = 10%
2. Find the M.P., if
(a) S.P. = ` 1,920 and Discount = 4% (b) S.P. = ` 1,098 and Discount = 8.5%
3. Find the rate of discount, if
(a) M.P. = ` 250 and S.P. = ` 235 (b) M.P. = ` 1,880 and S.P. = ` 1,504
4. Santosh purchased a wrist watch at 20% discount on its marked price and sold it at the marked price.
Find the profit per cent of Santosh on this transaction.
5. A cycle merchant allows 25% discount on the marked price of the cycles and still makes a profit of 20%.
If he earns a profit of ` 360 on the sale of one cycle, find the marked price of the cycle.
[Hint: First find the C.P. of the cycle.]
6. A shopkeeper offers 10% off-season discount and still makes a profit of 26%. What is the cost price for
the shopkeeper of a pair of shoes marked at ` 1,120?
7. How much per cent above the cost price should a shopkeeper mark his goods so that after allowing a
discount of 10% on the marked price, he earns a profit of 8%?
8. A trader offers two successive discounts of 10% and 8% on an article whose marked price is ` 4,600. Find
its selling price.
9. Which is more favourable to the seller and by how much—` 800 with 20% discount or the same amount
with successive discounts of 12% and 10%?
10. A mobile phone was marked at 35% above the cost price and a discount of 20% was given on the marked
price. Find the profit % or loss % made by the shopkeeper.
11. A laptop was marked at ` 32,000. The shopkeeper announced a discount of 20% on the laptop. But
due to some defect in the laptop, he had to further give a discount 10%. At what price was the laptop
sold?

Tax
To raise funds for spending on public benefits such as construction of roads, hospitals and to meet other
governmental expenses, the government levy taxes on the sale of goods. This tax is calculated on the selling
price and is added to the cost of goods and services. In case discount is applicable, it is first deducted and
then tax is applied on the net selling price. If there is no discount then the selling price will be the same as
the marked price.

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