PSLE A stationery 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.
Vanessa and Justin each bought two books at the sale.
- Vanessa's books were priced at $30 and $34. How much less did she pay for the 2nd book than the 1st book?
- Justin paid a total of $42.75 for his two books. He paid $8.25 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $34 |
100% $30 |
|
Discount |
- 15% |
- 25% |
|
Sale price |
85% |
75% |
? |
(a)
Selling price of the 1st book
= 85% x 34
=
85100 x 34
= $28.90
Selling price of 2nd book
= 75% x 30
=
75100 x 30
= $22.50
Amount that Vanessa paid less for the 2nd book than the 1st book
= 28.90 - 22.50
= $6.40
|
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 + $8.25 |
1 u |
$42.75 |
(b)
Sale price of the 1st book = 1 u + 8.25
Sale price of the 2nd book = 1 u
Total amount that Justin paid
= 1 u + 8.25 + 1 u
= 2 u + 8.25
2 u + 8.25 = 42.75
2 u = 42.75 - 8.25
2 u = 34.50
1 u = 34.50 ÷ 2 = 17.25
Sale price of the 1st book
= 1 u + 8.25
= $25.50
85% of the price = $25.50
100% of the price =
25.5085 x 100 = $30
Selling price of the 1st book before discount = $30
Answer(s): (a) $6.40; (b) $30