PSLE A store is having a book sale.
The 1st book is at 20% discount.
The 2nd book is at 25% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Fanny and Peter each bought two books at the sale.
- Fanny's books were priced at $10 and $21. How much less did she pay for the 2nd book than the 1st book?
- Peter paid a total of $53.65 for his two books. He paid $7.15 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $21 |
100% $10 |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80% |
75% |
? |
(a)
Selling price of the 1st book
= 80% x 21
=
80100 x 21
= $16.80
Selling price of 2nd book
= 75% x 10
=
75100 x 10
= $7.50
Amount that Fanny paid less for the 2nd book than the 1st book
= 16.80 - 7.50
= $9.30
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $7.15 |
1 u |
$53.65 |
(b)
Sale price of the 1st book = 1 u + 7.15
Sale price of the 2nd book = 1 u
Total amount that Peter paid
= 1 u + 7.15 + 1 u
= 2 u + 7.15
2 u + 7.15 = 53.65
2 u = 53.65 - 7.15
2 u = 46.50
1 u = 46.50 ÷ 2 = 23.25
Sale price of the 1st book
= 1 u + 7.15
= $30.40
80% of the price = $30.40
100% of the price =
30.4080 x 100 = $38
Selling price of the 1st book before discount = $38
Answer(s): (a) $9.30; (b) $38