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.
Opal and George each bought two books at the sale.
- Opal's books were priced at $15 and $17. How much less did she pay for the 2nd book than the 1st book?
- George paid a total of $42.25 for his two books. He paid $9.95 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% $17 |
100% $15 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 17
=
90100 x 17
= $15.30
Selling price of 2nd book
= 85% x 15
=
85100 x 15
= $12.75
Amount that Opal paid less for the 2nd book than the 1st book
= 15.30 - 12.75
= $2.55
|
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 + $9.95 |
1 u |
$42.25 |
(b)
Sale price of the 1st book = 1 u + 9.95
Sale price of the 2nd book = 1 u
Total amount that George paid
= 1 u + 9.95 + 1 u
= 2 u + 9.95
2 u + 9.95 = 42.25
2 u = 42.25 - 9.95
2 u = 32.30
1 u = 32.30 ÷ 2 = 16.15
Sale price of the 1st book
= 1 u + 9.95
= $26.10
90% of the price = $26.10
100% of the price =
26.1090 x 100 = $29
Selling price of the 1st book before discount = $29
Answer(s): (a) $2.55; (b) $29