PSLE A stationery shop is having a book sale.
The 1st book is at 25% discount.
The 2nd book is at 40% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Cathy and Justin each bought two books at the sale.
- Cathy's books were priced at $17 and $21. How much did she pay for them?
- Justin paid a total of $43.35 for his two books. He paid $6.15 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% $21 |
100% $17 |
|
Discount |
- 25% |
- 40% |
|
Sale price |
75% |
60% |
? |
(a)
Selling price of the 1st book
= 75% x 21
=
75100 x 21
= $15.75
Selling price of 2nd book
= 60% x 17
=
60100 x 17
= $10.20
Total amount that Cathy paid
= 15.75 + 10.20
= $25.95
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 25% |
- 40% |
|
Sale price |
75%
|
60%
|
|
Compare 1st book and 2nd book |
1 u + $6.15 |
1 u |
$43.35 |
(b)
Sale price of the 1st book = 1 u + 6.15
Sale price of the 2nd book = 1 u
Total amount that Justin paid
= 1 u + 6.15 + 1 u
= 2 u + 6.15
2 u + 6.15 = 43.35
2 u = 43.35 - 6.15
2 u = 37.20
1 u = 37.20 ÷ 2 = 18.60
Sale price of the 2nd book = $18.60
60% of the price = $18.60
100% of the price =
18.6060 x 100 = $31
Selling price of the 2nd book before discount = $31
Answer(s): (a) $25.95; (b) $31