PSLE A stationery shop is having a book sale.
The 1st book is at 15% 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.
Kathy and Jenson each bought two books at the sale.
- Kathy's books were priced at $9 and $17. How much more did she pay for the 1st book than the 2nd book?
- Jenson paid a total of $50.60 for his two books. He paid $7.20 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% $17 |
100% $9 |
|
Discount |
- 15% |
- 30% |
|
Sale price |
85% |
70% |
? |
(a)
Selling price of the 1st book
= 85% x 17
=
85100 x 17
= $14.45
Selling price of 2nd book
= 70% x 9
=
70100 x 9
= $6.30
Amount that Kathy paid more for the 1st book than the 2nd book
= 14.45 - 6.30
= $8.15
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 30% |
|
Sale price |
85%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $7.20 |
1 u |
$50.60 |
(b)
Sale price of the 1st book = 1 u + 7.20
Sale price of the 2nd book = 1 u
Total amount that Jenson paid
= 1 u + 7.20 + 1 u
= 2 u + 7.20
2 u + 7.20 = 50.60
2 u = 50.60 - 7.20
2 u = 43.40
1 u = 43.40 ÷ 2 = 21.70
Sale price of the 1st book
= 1 u + 7.20
= $28.90
85% of the price = $28.90
100% of the price =
28.9085 x 100 = $34
Selling price of the 1st book before discount = $34
Answer(s): (a) $8.15; (b) $34