PSLE A book shop is having a book sale.
The 1st book is at 20% 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.
Dana and Caden each bought two books at the sale.
- Dana's books were priced at $7 and $18. How much more did she pay for the 1st book than the 2nd book?
- Caden paid a total of $49.20 for his two books. He paid $8.40 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% $18 |
100% $7 |
|
Discount |
- 20% |
- 40% |
|
Sale price |
80% |
60% |
? |
(a)
Selling price of the 1st book
= 80% x 18
=
80100 x 18
= $14.40
Selling price of 2nd book
= 60% x 7
=
60100 x 7
= $4.20
Amount that Dana paid more for the 1st book than the 2nd book
= 14.40 - 4.20
= $10.20
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 40% |
|
Sale price |
80%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $8.40 |
1 u |
$49.20 |
(b)
Sale price of the 1st book = 1 u + 8.40
Sale price of the 2nd book = 1 u
Total amount that Caden paid
= 1 u + 8.40 + 1 u
= 2 u + 8.40
2 u + 8.40 = 49.20
2 u = 49.20 - 8.40
2 u = 40.80
1 u = 40.80 ÷ 2 = 20.40
Sale price of the 1st book
= 1 u + 8.40
= $28.80
80% of the price = $28.80
100% of the price =
28.8080 x 100 = $36
Selling price of the 1st book before discount = $36
Answer(s): (a) $10.20; (b) $36