PSLE A book shop is having a book sale. The 1st book is at 15% 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.
- Eva's books were priced at $33 and $38. How much more did she pay for the 1st book than the 2nd book?
- Luis paid a total of $36.15 for his two books. He paid $4.65 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% $38 |
100% $33 |
|
Discount |
- 15% |
- 25% |
|
Sale price |
85% |
75% |
? |
(a)
Selling price of the 1st book
= 85% x 38
=
85100 x 38
= $32.30
Selling price of 2nd book
= 75% x 33
=
75100 x 33
= $24.75
Amount that Eva paid more for the 1st book than the 2nd book
= 32.30 - 24.75
= $7.55
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 25% |
|
Sale price |
85%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $4.65 |
1 u |
$36.15 |
(b)
Sale price of the 1st book = 1 u + 4.65
Sale price of the 2nd book = 1 u
Total amount that Luis paid
= 1 u + 4.65 + 1 u
= 2 u + 4.65
2 u + 4.65 = 36.15
2 u = 36.15 - 4.65
2 u = 31.50
1 u = 31.50 ÷ 2 = 15.75
Sale price of the 1st book
= 1 u + 4.65
= $20.40
85% of the price = $20.40
100% of the price =
20.4085 x 100 = $24
Selling price of the 1st book before discount = $24
Answer(s): (a) $7.55; (b) $24