PSLE A bookstore 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.
Marion and Vaidev each bought two books at the sale.
- Marion's books were priced at $18 and $25. How much more did she pay for the 1st book than the 2nd book?
- Vaidev paid a total of $39.50 for his two books. He paid $9.10 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% $25 |
100% $18 |
|
Discount |
- 10% |
- 20% |
|
Sale price |
90% |
80% |
? |
(a)
Selling price of the 1st book
= 90% x 25
=
90100 x 25
= $22.50
Selling price of 2nd book
= 80% x 18
=
80100 x 18
= $14.40
Amount that Marion paid more for the 1st book than the 2nd book
= 22.50 - 14.40
= $8.10
|
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 + $9.10 |
1 u |
$39.50 |
(b)
Sale price of the 1st book = 1 u + 9.10
Sale price of the 2nd book = 1 u
Total amount that Vaidev paid
= 1 u + 9.10 + 1 u
= 2 u + 9.10
2 u + 9.10 = 39.50
2 u = 39.50 - 9.10
2 u = 30.40
1 u = 30.40 ÷ 2 = 15.20
Sale price of the 1st book
= 1 u + 9.10
= $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) $8.10; (b) $27