PSLE A shop is having a book sale.
The 1st book is at 20% discount.
The 2nd book is at 30% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Marion and Cody each bought two books at the sale.
- Marion's books were priced at $2 and $16. How much less did she pay for the 2nd book than the 1st book?
- Cody paid a total of $33.90 for his two books. He paid $4.50 more for the 1st book than for the 2nd book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $16 |
100% $2 |
|
Discount |
- 20% |
- 30% |
|
Sale price |
80% |
70% |
? |
(a)
Selling price of the 1st book
= 80% x 16
=
80100 x 16
= $12.80
Selling price of 2nd book
= 70% x 2
=
70100 x 2
= $1.40
Amount that Marion paid less for the 2nd book than the 1st book
= 12.80 - 1.40
= $11.40
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 30% |
|
Sale price |
80%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $4.50 |
1 u |
$33.90 |
(b)
Sale price of the 1st book = 1 u + 4.50
Sale price of the 2nd book = 1 u
Total amount that Cody paid
= 1 u + 4.50 + 1 u
= 2 u + 4.50
2 u + 4.50 = 33.90
2 u = 33.90 - 4.50
2 u = 29.40
1 u = 29.40 ÷ 2 = 14.70
Sale price of the 1st book
= 1 u + 4.50
= $19.20
80% of the price = $19.20
100% of the price =
19.2080 x 100 = $24
Selling price of the 1st book before discount = $24
Answer(s): (a) $11.40; (b) $24