PSLE A stationery shop is having a book sale.
The 1st book is at 5% discount.
The 2nd book is at 15% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Mary and Tommy each bought two books at the sale.
- Mary's books were priced at $9 and $19. How much did she pay for them?
- Tommy paid a total of $63.20 for his two books. He paid $7.10 less for the 2nd book than the 1st book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $19 |
100% $9 |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95% |
85% |
? |
(a)
Selling price of the 1st book
= 95% x 19
=
95100 x 19
= $18.05
Selling price of 2nd book
= 85% x 9
=
85100 x 9
= $7.65
Total amount that Mary paid
= 18.05 + 7.65
= $25.70
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $7.10 |
1 u |
$63.20 |
(b)
Sale price of the 1st book = 1 u + 7.10
Sale price of the 2nd book = 1 u
Total amount that Tommy paid
= 1 u + 7.10 + 1 u
= 2 u + 7.10
2 u + 7.10 = 63.20
2 u = 63.20 - 7.10
2 u = 56.10
1 u = 56.10 ÷ 2 = 28.05
Sale price of the 2nd book = $28.05
85% of the price = $28.05
100% of the price =
28.0585 x 100 = $33
Selling price of the 2nd book before discount = $33
Answer(s): (a) $25.70; (b) $33