PSLE A stationery kiosk 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.
Wendy and Billy each bought two books at the sale.
- Wendy's books were priced at $23 and $32. How much less did she pay for the 2nd book than the 1st book?
- Billy paid a total of $53.60 for his two books. He paid $9.40 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% $32 |
100% $23 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 32
=
90100 x 32
= $28.80
Selling price of 2nd book
= 85% x 23
=
85100 x 23
= $19.55
Amount that Wendy paid less for the 2nd book than the 1st book
= 28.80 - 19.55
= $9.25
|
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 + $9.40 |
1 u |
$53.60 |
(b)
Sale price of the 1st book = 1 u + 9.40
Sale price of the 2nd book = 1 u
Total amount that Billy paid
= 1 u + 9.40 + 1 u
= 2 u + 9.40
2 u + 9.40 = 53.60
2 u = 53.60 - 9.40
2 u = 44.20
1 u = 44.20 ÷ 2 = 22.10
Sale price of the 1st book
= 1 u + 9.40
= $31.50
90% of the price = $31.50
100% of the price =
31.5090 x 100 = $35
Selling price of the 1st book before discount = $35
Answer(s): (a) $9.25; (b) $35