PSLE A book shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 15% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Hilda and Ben each bought two books at the sale.
- Hilda's books were priced at $17 and $31. How much more did she pay for the 1st book than the 2nd book?
- Ben paid a total of $55.35 for his two books. He paid $9.45 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% $31 |
100% $17 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 31
=
90100 x 31
= $27.90
Selling price of 2nd book
= 85% x 17
=
85100 x 17
= $14.45
Amount that Hilda paid more for the 1st book than the 2nd book
= 27.90 - 14.45
= $13.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $9.45 |
1 u |
$55.35 |
(b)
Sale price of the 1st book = 1 u + 9.45
Sale price of the 2nd book = 1 u
Total amount that Ben paid
= 1 u + 9.45 + 1 u
= 2 u + 9.45
2 u + 9.45 = 55.35
2 u = 55.35 - 9.45
2 u = 45.90
1 u = 45.90 ÷ 2 = 22.95
Sale price of the 1st book
= 1 u + 9.45
= $32.40
90% of the price = $32.40
100% of the price =
32.4090 x 100 = $36
Selling price of the 1st book before discount = $36
Answer(s): (a) $13.45; (b) $36