PSLE A book shop is having a book sale. The 1st book is at 25% discount. The 2nd book is at 40% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Usha's books were priced at $14 and $27. How much more did she pay for the 1st book than the 2nd book?
- Carl paid a total of $32.85 for his two books. He paid $7.65 more for the 1st book than for the 2nd book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $27 |
100% $14 |
|
Discount |
- 25% |
- 40% |
|
Sale price |
75% |
60% |
? |
(a)
Selling price of the 1st book
= 75% x 27
=
75100 x 27
= $20.25
Selling price of 2nd book
= 60% x 14
=
60100 x 14
= $8.40
Amount that Usha paid more for the 1st book than the 2nd book
= 20.25 - 8.40
= $11.85
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 25% |
- 40% |
|
Sale price |
75%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $7.65 |
1 u |
$32.85 |
(b)
Sale price of the 1st book = 1 u + 7.65
Sale price of the 2nd book = 1 u
Total amount that Carl paid
= 1 u + 7.65 + 1 u
= 2 u + 7.65
2 u + 7.65 = 32.85
2 u = 32.85 - 7.65
2 u = 25.20
1 u = 25.20 ÷ 2 = 12.60
Sale price of the 1st book
= 1 u + 7.65
= $20.25
75% of the price = $20.25
100% of the price =
20.2575 x 100 = $27
Selling price of the 1st book before discount = $27
Answer(s): (a) $11.85; (b) $27