PSLE A shop is having a book sale.
The 1st book is at 25% discount.
The 2nd book is at 35% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Betty and Tommy each bought two books at the sale.
- Betty's books were priced at $17 and $30. How much less did she pay for the 2nd book than the 1st book?
- Tommy paid a total of $34.10 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% $30 |
100% $17 |
|
Discount |
- 25% |
- 35% |
|
Sale price |
75% |
65% |
? |
(a)
Selling price of the 1st book
= 75% x 30
=
75100 x 30
= $22.50
Selling price of 2nd book
= 65% x 17
=
65100 x 17
= $11.05
Amount that Betty paid less for the 2nd book than the 1st book
= 22.50 - 11.05
= $11.45
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 25% |
- 35% |
|
Sale price |
75%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $9.40 |
1 u |
$34.10 |
(b)
Sale price of the 1st book = 1 u + 9.40
Sale price of the 2nd book = 1 u
Total amount that Tommy paid
= 1 u + 9.40 + 1 u
= 2 u + 9.40
2 u + 9.40 = 34.10
2 u = 34.10 - 9.40
2 u = 24.70
1 u = 24.70 ÷ 2 = 12.35
Sale price of the 1st book
= 1 u + 9.40
= $21.75
75% of the price = $21.75
100% of the price =
21.7575 x 100 = $29
Selling price of the 1st book before discount = $29
Answer(s): (a) $11.45; (b) $29