PSLE A bookstore is having a book sale. The 1st book is at 20% discount. The 2nd book is at 25% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Gillian's books were priced at $6 and $18. How much less did she pay for the 2nd book than the 1st book?
- Eric paid a total of $53.55 for his two books. He paid $4.05 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% $6 |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80% |
75% |
? |
(a)
Selling price of the 1st book
= 80% x 18
=
80100 x 18
= $14.40
Selling price of 2nd book
= 75% x 6
=
75100 x 6
= $4.50
Amount that Gillian paid less for the 2nd book than the 1st book
= 14.40 - 4.50
= $9.90
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $4.05 |
1 u |
$53.55 |
(b)
Sale price of the 1st book = 1 u + 4.05
Sale price of the 2nd book = 1 u
Total amount that Eric paid
= 1 u + 4.05 + 1 u
= 2 u + 4.05
2 u + 4.05 = 53.55
2 u = 53.55 - 4.05
2 u = 49.50
1 u = 49.50 ÷ 2 = 24.75
Sale price of the 1st book
= 1 u + 4.05
= $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) $9.90; (b) $36