PSLE A shop is having a book sale. The 1st book is at 10% 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.
- Kylie's books were priced at $5 and $14. How much did she pay for them?
- David paid a total of $28.65 for his two books. He paid $9.15 more for the 1st book than the 2nd book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $14 |
100% $5 |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90% |
75% |
? |
(a)
Selling price of the 1st book
= 90% x 14
=
90100 x 14
= $12.60
Selling price of 2nd book
= 75% x 5
=
75100 x 5
= $3.75
Total amount that Kylie paid
= 12.60 + 3.75
= $16.35
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 25% |
|
Sale price |
90%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $9.15 |
1 u |
$28.65 |
(b)
Sale price of the 1st book = 1 u + 9.15
Sale price of the 2nd book = 1 u
Total amount that David paid
= 1 u + 9.15 + 1 u
= 2 u + 9.15
2 u + 9.15 = 28.65
2 u = 28.65 - 9.15
2 u = 19.50
1 u = 19.50 ÷ 2 = 9.75
Sale price of the 2nd book = $9.75
75% of the price = $9.75
100% of the price =
9.7575 x 100 = $13
Selling price of the 2nd book before discount = $13
Answer(s): (a) $16.35; (b) $13