PSLE A stationery shop is having a book sale. The 1st book is at 5% 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.
- Jane's books were priced at $15 and $21. How much less did she pay for the 2nd book than the 1st book?
- Will paid a total of $66.70 for his two books. He paid $5.50 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% $21 |
100% $15 |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95% |
85% |
? |
(a)
Selling price of the 1st book
= 95% x 21
=
95100 x 21
= $19.95
Selling price of 2nd book
= 85% x 15
=
85100 x 15
= $12.75
Amount that Jane paid less for the 2nd book than the 1st book
= 19.95 - 12.75
= $7.20
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $5.50 |
1 u |
$66.70 |
(b)
Sale price of the 1st book = 1 u + 5.50
Sale price of the 2nd book = 1 u
Total amount that Will paid
= 1 u + 5.50 + 1 u
= 2 u + 5.50
2 u + 5.50 = 66.70
2 u = 66.70 - 5.50
2 u = 61.20
1 u = 61.20 ÷ 2 = 30.60
Sale price of the 1st book
= 1 u + 5.50
= $36.10
95% of the price = $36.10
100% of the price =
36.1095 x 100 = $38
Selling price of the 1st book before discount = $38
Answer(s): (a) $7.20; (b) $38