PSLE A book shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 20% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Gem and Gabriel each bought two books at the sale.
- Gem's books were priced at $1 and $15. How much did she pay for them?
- Gabriel paid a total of $53.10 for his two books. He paid $9.90 more for the 1st book than the 2nd book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $15 |
100% $1 |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90% |
80% |
? |
(a)
Selling price of the 1st book
= 90% x 15
=
90100 x 15
= $13.50
Selling price of 2nd book
= 80% x 1
=
80100 x 1
= $0.80
Total amount that Gem paid
= 13.50 + 0.80
= $14.30
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90%
|
80%
|
|
Compare 1st book and 2nd book |
1 u + $9.90 |
1 u |
$53.10 |
(b)
Sale price of the 1st book = 1 u + 9.90
Sale price of the 2nd book = 1 u
Total amount that Gabriel paid
= 1 u + 9.90 + 1 u
= 2 u + 9.90
2 u + 9.90 = 53.10
2 u = 53.10 - 9.90
2 u = 43.20
1 u = 43.20 ÷ 2 = 21.60
Sale price of the 2nd book = $21.60
80% of the price = $21.60
100% of the price =
21.6080 x 100 = $27
Selling price of the 2nd book before discount = $27
Answer(s): (a) $14.30; (b) $27