PSLE A stationery shop is having a book sale. The 1st book is at 5% 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.
- Cathy's books were priced at $21 and $29. How much less did she pay for the 2nd book than the 1st book?
- Ken paid a total of $57.25 for his two books. He paid $13.05 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% $29 |
100% $21 |
|
Discount |
- 5% |
- 35% |
|
Sale price |
95% |
65% |
? |
(a)
Selling price of the 1st book
= 95% x 29
=
95100 x 29
= $27.55
Selling price of 2nd book
= 65% x 21
=
65100 x 21
= $13.65
Amount that Cathy paid less for the 2nd book than the 1st book
= 27.55 - 13.65
= $13.90
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 35% |
|
Sale price |
95%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $13.05 |
1 u |
$57.25 |
(b)
Sale price of the 1st book = 1 u + 13.05
Sale price of the 2nd book = 1 u
Total amount that Ken paid
= 1 u + 13.05 + 1 u
= 2 u + 13.05
2 u + 13.05 = 57.25
2 u = 57.25 - 13.05
2 u = 44.20
1 u = 44.20 ÷ 2 = 22.10
Sale price of the 1st book
= 1 u + 13.05
= $35.15
95% of the price = $35.15
100% of the price =
35.1595 x 100 = $37
Selling price of the 1st book before discount = $37
Answer(s): (a) $13.90; (b) $37