PSLE A store is having a book sale.
The 1st book is at 15% 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.
Irene and Sam each bought two books at the sale.
- Irene's books were priced at $18 and $23. How much more did she pay for the 1st book than the 2nd book?
- Sam paid a total of $41.70 for his two books. He paid $4.20 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% $23 |
100% $18 |
|
Discount |
- 15% |
- 25% |
|
Sale price |
85% |
75% |
? |
(a)
Selling price of the 1st book
= 85% x 23
=
85100 x 23
= $19.55
Selling price of 2nd book
= 75% x 18
=
75100 x 18
= $13.50
Amount that Irene paid more for the 1st book than the 2nd book
= 19.55 - 13.50
= $6.05
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 25% |
|
Sale price |
85%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $4.20 |
1 u |
$41.70 |
(b)
Sale price of the 1st book = 1 u + 4.20
Sale price of the 2nd book = 1 u
Total amount that Sam paid
= 1 u + 4.20 + 1 u
= 2 u + 4.20
2 u + 4.20 = 41.70
2 u = 41.70 - 4.20
2 u = 37.50
1 u = 37.50 ÷ 2 = 18.75
Sale price of the 1st book
= 1 u + 4.20
= $22.95
85% of the price = $22.95
100% of the price =
22.9585 x 100 = $27
Selling price of the 1st book before discount = $27
Answer(s): (a) $6.05; (b) $27