PSLE A shop is having a book sale.
The 1st book is at 15% discount.
The 2nd book is at 30% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Shannon and George each bought two books at the sale.
- Shannon's books were priced at $29 and $37. How much more did she pay for the 1st book than the 2nd book?
- George paid a total of $29.90 for his two books. He paid $7.50 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% $37 |
100% $29 |
|
Discount |
- 15% |
- 30% |
|
Sale price |
85% |
70% |
? |
(a)
Selling price of the 1st book
= 85% x 37
=
85100 x 37
= $31.45
Selling price of 2nd book
= 70% x 29
=
70100 x 29
= $20.30
Amount that Shannon paid more for the 1st book than the 2nd book
= 31.45 - 20.30
= $11.15
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 15% |
- 30% |
|
Sale price |
85%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $7.50 |
1 u |
$29.90 |
(b)
Sale price of the 1st book = 1 u + 7.50
Sale price of the 2nd book = 1 u
Total amount that George paid
= 1 u + 7.50 + 1 u
= 2 u + 7.50
2 u + 7.50 = 29.90
2 u = 29.90 - 7.50
2 u = 22.40
1 u = 22.40 ÷ 2 = 11.20
Sale price of the 1st book
= 1 u + 7.50
= $18.70
85% of the price = $18.70
100% of the price =
18.7085 x 100 = $22
Selling price of the 1st book before discount = $22
Answer(s): (a) $11.15; (b) $22