PSLE A bookstore is having a book sale.
The 1st book is at 10% discount.
The 2nd book is at 15% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Mary and Andy each bought two books at the sale.
- Mary's books were priced at $23 and $26. How much more did she pay for the 1st book than the 2nd book?
- Andy paid a total of $53.55 for his two books. He paid $7.65 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% $26 |
100% $23 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 26
=
90100 x 26
= $23.40
Selling price of 2nd book
= 85% x 23
=
85100 x 23
= $19.55
Amount that Mary paid more for the 1st book than the 2nd book
= 23.40 - 19.55
= $3.85
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $7.65 |
1 u |
$53.55 |
(b)
Sale price of the 1st book = 1 u + 7.65
Sale price of the 2nd book = 1 u
Total amount that Andy paid
= 1 u + 7.65 + 1 u
= 2 u + 7.65
2 u + 7.65 = 53.55
2 u = 53.55 - 7.65
2 u = 45.90
1 u = 45.90 ÷ 2 = 22.95
Sale price of the 1st book
= 1 u + 7.65
= $30.60
90% of the price = $30.60
100% of the price =
30.6090 x 100 = $34
Selling price of the 1st book before discount = $34
Answer(s): (a) $3.85; (b) $34