PSLE A stationery 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.
Gwen and Ivan each bought two books at the sale.
- Gwen's books were priced at $21 and $23. How much less did she pay for the 2nd book than the 1st book?
- Ivan paid a total of $48.45 for his two books. He paid $10.05 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% $23 |
100% $21 |
|
Discount |
- 25% |
- 40% |
|
Sale price |
75% |
60% |
? |
(a)
Selling price of the 1st book
= 75% x 23
=
75100 x 23
= $17.25
Selling price of 2nd book
= 60% x 21
=
60100 x 21
= $12.60
Amount that Gwen paid less for the 2nd book than the 1st book
= 17.25 - 12.60
= $4.65
|
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 + $10.05 |
1 u |
$48.45 |
(b)
Sale price of the 1st book = 1 u + 10.05
Sale price of the 2nd book = 1 u
Total amount that Ivan paid
= 1 u + 10.05 + 1 u
= 2 u + 10.05
2 u + 10.05 = 48.45
2 u = 48.45 - 10.05
2 u = 38.40
1 u = 38.40 ÷ 2 = 19.20
Sale price of the 1st book
= 1 u + 10.05
= $29.25
75% of the price = $29.25
100% of the price =
29.2575 x 100 = $39
Selling price of the 1st book before discount = $39
Answer(s): (a) $4.65; (b) $39