PSLE A book shop is having a book sale.
The 1st book is at 10% 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.
Gem and Carl each bought two books at the sale.
- Gem's books were priced at $11 and $16. How much less did she pay for the 2nd book than the 1st book?
- Carl paid a total of $40.05 for his two books. He paid $8.55 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% $16 |
100% $11 |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90% |
75% |
? |
(a)
Selling price of the 1st book
= 90% x 16
=
90100 x 16
= $14.40
Selling price of 2nd book
= 75% x 11
=
75100 x 11
= $8.25
Amount that Gem paid less for the 2nd book than the 1st book
= 14.40 - 8.25
= $6.15
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $8.55 |
1 u |
$40.05 |
(b)
Sale price of the 1st book = 1 u + 8.55
Sale price of the 2nd book = 1 u
Total amount that Carl paid
= 1 u + 8.55 + 1 u
= 2 u + 8.55
2 u + 8.55 = 40.05
2 u = 40.05 - 8.55
2 u = 31.50
1 u = 31.50 ÷ 2 = 15.75
Sale price of the 1st book
= 1 u + 8.55
= $24.30
90% of the price = $24.30
100% of the price =
24.3090 x 100 = $27
Selling price of the 1st book before discount = $27
Answer(s): (a) $6.15; (b) $27