PSLE A 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 Lee each bought two books at the sale.
- Gem's books were priced at $11 and $15. How much less did she pay for the 2nd book than the 1st book?
- Lee paid a total of $43.05 for his two books. He paid $5.55 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% $15 |
100% $11 |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90% |
75% |
? |
(a)
Selling price of the 1st book
= 90% x 15
=
90100 x 15
= $13.50
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
= 13.50 - 8.25
= $5.25
|
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 + $5.55 |
1 u |
$43.05 |
(b)
Sale price of the 1st book = 1 u + 5.55
Sale price of the 2nd book = 1 u
Total amount that Lee paid
= 1 u + 5.55 + 1 u
= 2 u + 5.55
2 u + 5.55 = 43.05
2 u = 43.05 - 5.55
2 u = 37.50
1 u = 37.50 ÷ 2 = 18.75
Sale price of the 1st book
= 1 u + 5.55
= $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) $5.25; (b) $27