PSLE A store is having a book sale.
The 1st book is at 20% discount.
The 2nd book is at 25% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Cathy and Harry each bought two books at the sale.
- Cathy's books were priced at $10 and $19. How much less did she pay for the 2nd book than the 1st book?
- Harry paid a total of $46.55 for his two books. He paid $3.05 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% $19 |
100% $10 |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80% |
75% |
? |
(a)
Selling price of the 1st book
= 80% x 19
=
80100 x 19
= $15.20
Selling price of 2nd book
= 75% x 10
=
75100 x 10
= $7.50
Amount that Cathy paid less for the 2nd book than the 1st book
= 15.20 - 7.50
= $7.70
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 20% |
- 25% |
|
Sale price |
80%
|
75%
|
|
Compare 1st book and 2nd book |
1 u + $3.05 |
1 u |
$46.55 |
(b)
Sale price of the 1st book = 1 u + 3.05
Sale price of the 2nd book = 1 u
Total amount that Harry paid
= 1 u + 3.05 + 1 u
= 2 u + 3.05
2 u + 3.05 = 46.55
2 u = 46.55 - 3.05
2 u = 43.50
1 u = 43.50 ÷ 2 = 21.75
Sale price of the 1st book
= 1 u + 3.05
= $24.80
80% of the price = $24.80
100% of the price =
24.8080 x 100 = $31
Selling price of the 1st book before discount = $31
Answer(s): (a) $7.70; (b) $31