PSLE A stationery shop is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 35% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Anna and Simon each bought two books at the sale.
- Anna's books were priced at $12 and $13. How much more did she pay for the 1st book than the 2nd book?
- Simon paid a total of $54.10 for his two books. He paid $12.50 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% $13 |
100% $12 |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90% |
65% |
? |
(a)
Selling price of the 1st book
= 90% x 13
=
90100 x 13
= $11.70
Selling price of 2nd book
= 65% x 12
=
65100 x 12
= $7.80
Amount that Anna paid more for the 1st book than the 2nd book
= 11.70 - 7.80
= $3.90
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 35% |
|
Sale price |
90%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $12.50 |
1 u |
$54.10 |
(b)
Sale price of the 1st book = 1 u + 12.50
Sale price of the 2nd book = 1 u
Total amount that Simon paid
= 1 u + 12.50 + 1 u
= 2 u + 12.50
2 u + 12.50 = 54.10
2 u = 54.10 - 12.50
2 u = 41.60
1 u = 41.60 ÷ 2 = 20.80
Sale price of the 1st book
= 1 u + 12.50
= $33.30
90% of the price = $33.30
100% of the price =
33.3090 x 100 = $37
Selling price of the 1st book before discount = $37
Answer(s): (a) $3.90; (b) $37