PSLE A shop is having a book sale.
The 1st book is at 5% discount.
The 2nd book is at 40% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Sarah and Oscar each bought two books at the sale.
- Sarah's books were priced at $21 and $35. How much less did she pay for the 2nd book than the 1st book?
- Oscar paid a total of $54.70 for his two books. He paid $17.50 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% $35 |
100% $21 |
|
Discount |
- 5% |
- 40% |
|
Sale price |
95% |
60% |
? |
(a)
Selling price of the 1st book
= 95% x 35
=
95100 x 35
= $33.25
Selling price of 2nd book
= 60% x 21
=
60100 x 21
= $12.60
Amount that Sarah paid less for the 2nd book than the 1st book
= 33.25 - 12.60
= $20.65
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 40% |
|
Sale price |
95%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $17.50 |
1 u |
$54.70 |
(b)
Sale price of the 1st book = 1 u + 17.50
Sale price of the 2nd book = 1 u
Total amount that Oscar paid
= 1 u + 17.50 + 1 u
= 2 u + 17.50
2 u + 17.50 = 54.70
2 u = 54.70 - 17.50
2 u = 37.20
1 u = 37.20 ÷ 2 = 18.60
Sale price of the 1st book
= 1 u + 17.50
= $36.10
95% of the price = $36.10
100% of the price =
36.1095 x 100 = $38
Selling price of the 1st book before discount = $38
Answer(s): (a) $20.65; (b) $38