PSLE A stationery shop is having a book sale.
The 1st book is at 20% 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.
Cindy and Daniel each bought two books at the sale.
- Cindy's books were priced at $27 and $31. How much more did she pay for the 1st book than the 2nd book?
- Daniel paid a total of $38.15 for his two books. He paid $6.65 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% $31 |
100% $27 |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80% |
75% |
? |
(a)
Selling price of the 1st book
= 80% x 31
=
80100 x 31
= $24.80
Selling price of 2nd book
= 75% x 27
=
75100 x 27
= $20.25
Amount that Cindy paid more for the 1st book than the 2nd book
= 24.80 - 20.25
= $4.55
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $6.65 |
1 u |
$38.15 |
(b)
Sale price of the 1st book = 1 u + 6.65
Sale price of the 2nd book = 1 u
Total amount that Daniel paid
= 1 u + 6.65 + 1 u
= 2 u + 6.65
2 u + 6.65 = 38.15
2 u = 38.15 - 6.65
2 u = 31.50
1 u = 31.50 ÷ 2 = 15.75
Sale price of the 1st book
= 1 u + 6.65
= $22.40
80% of the price = $22.40
100% of the price =
22.4080 x 100 = $28
Selling price of the 1st book before discount = $28
Answer(s): (a) $4.55; (b) $28