PSLE A stationery 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.
Dana and Paul each bought two books at the sale.
- Dana's books were priced at $1 and $14. How much less did she pay for the 2nd book than the 1st book?
- Paul paid a total of $50.05 for his two books. He paid $7.55 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% $14 |
100% $1 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 14
=
90100 x 14
= $12.60
Selling price of 2nd book
= 85% x 1
=
85100 x 1
= $0.85
Amount that Dana paid less for the 2nd book than the 1st book
= 12.60 - 0.85
= $11.75
|
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 + $7.55 |
1 u |
$50.05 |
(b)
Sale price of the 1st book = 1 u + 7.55
Sale price of the 2nd book = 1 u
Total amount that Paul paid
= 1 u + 7.55 + 1 u
= 2 u + 7.55
2 u + 7.55 = 50.05
2 u = 50.05 - 7.55
2 u = 42.50
1 u = 42.50 ÷ 2 = 21.25
Sale price of the 1st book
= 1 u + 7.55
= $28.80
90% of the price = $28.80
100% of the price =
28.8090 x 100 = $32
Selling price of the 1st book before discount = $32
Answer(s): (a) $11.75; (b) $32