PSLE A store is having a book sale.
The 1st book is at 15% discount.
The 2nd book is at 20% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Irene and Ken each bought two books at the sale.
- Irene's books were priced at $9 and $10. How much did she pay for them?
- Ken paid a total of $29.10 for his two books. He paid $8.30 less for the 2nd book than the 1st book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $10 |
100% $9 |
|
Discount |
- 15% |
- 20% |
|
Sale price |
85% |
80% |
? |
(a)
Selling price of the 1st book
= 85% x 10
=
85100 x 10
= $8.50
Selling price of 2nd book
= 80% x 9
=
80100 x 9
= $7.20
Total amount that Irene paid
= 8.50 + 7.20
= $15.70
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 20% |
|
Sale price |
85%
|
80%
|
|
Compare 1st book and 2nd book |
1 u + $8.30 |
1 u |
$29.10 |
(b)
Sale price of the 1st book = 1 u + 8.30
Sale price of the 2nd book = 1 u
Total amount that Ken paid
= 1 u + 8.30 + 1 u
= 2 u + 8.30
2 u + 8.30 = 29.10
2 u = 29.10 - 8.30
2 u = 20.80
1 u = 20.80 ÷ 2 = 10.40
Sale price of the 2nd book = $10.40
80% of the price = $10.40
100% of the price =
10.4080 x 100 = $13
Selling price of the 2nd book before discount = $13
Answer(s): (a) $15.70; (b) $13