PSLE A shop is having a book sale. The 1st book is at 5% discount. The 2nd book is at 10% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Mary's books were priced at $15 and $28. How much less did she pay for the 2nd book than the 1st book?
- Bryan paid a total of $52.80 for his two books. He paid $4.20 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% $28 |
100% $15 |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95% |
90% |
? |
(a)
Selling price of the 1st book
= 95% x 28
=
95100 x 28
= $26.60
Selling price of 2nd book
= 90% x 15
=
90100 x 15
= $13.50
Amount that Mary paid less for the 2nd book than the 1st book
= 26.60 - 13.50
= $13.10
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 10% |
|
Sale price |
95%
|
90%
|
|
Compare 1st book and 2nd book |
1 u + $4.20 |
1 u |
$52.80 |
(b)
Sale price of the 1st book = 1 u + 4.20
Sale price of the 2nd book = 1 u
Total amount that Bryan paid
= 1 u + 4.20 + 1 u
= 2 u + 4.20
2 u + 4.20 = 52.80
2 u = 52.80 - 4.20
2 u = 48.60
1 u = 48.60 ÷ 2 = 24.30
Sale price of the 1st book
= 1 u + 4.20
= $28.50
95% of the price = $28.50
100% of the price =
28.5095 x 100 = $30
Selling price of the 1st book before discount = $30
Answer(s): (a) $13.10; (b) $30