PSLE A bookstore is having a book sale. The 1st book is at 10% 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.
- Ivory's books were priced at $18 and $19. How much more did she pay for the 1st book than the 2nd book?
- Owen paid a total of $44.30 for his two books. He paid $7.90 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% $19 |
100% $18 |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90% |
70% |
? |
(a)
Selling price of the 1st book
= 90% x 19
=
90100 x 19
= $17.10
Selling price of 2nd book
= 70% x 18
=
70100 x 18
= $12.60
Amount that Ivory paid more for the 1st book than the 2nd book
= 17.10 - 12.60
= $4.50
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 30% |
|
Sale price |
90%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $7.90 |
1 u |
$44.30 |
(b)
Sale price of the 1st book = 1 u + 7.90
Sale price of the 2nd book = 1 u
Total amount that Owen paid
= 1 u + 7.90 + 1 u
= 2 u + 7.90
2 u + 7.90 = 44.30
2 u = 44.30 - 7.90
2 u = 36.40
1 u = 36.40 ÷ 2 = 18.20
Sale price of the 1st book
= 1 u + 7.90
= $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) $4.50; (b) $29