PSLE A stationery shop is having a book sale. The 1st book is at 25% 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.
- Lynn's books were priced at $13 and $23. How much more did she pay for the 1st book than the 2nd book?
- Cody paid a total of $53.70 for his two books. He paid $3.30 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% $23 |
100% $13 |
|
Discount |
- 25% |
- 30% |
|
Sale price |
75% |
70% |
? |
(a)
Selling price of the 1st book
= 75% x 23
=
75100 x 23
= $17.25
Selling price of 2nd book
= 70% x 13
=
70100 x 13
= $9.10
Amount that Lynn paid more for the 1st book than the 2nd book
= 17.25 - 9.10
= $8.15
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 25% |
- 30% |
|
Sale price |
75%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $3.30 |
1 u |
$53.70 |
(b)
Sale price of the 1st book = 1 u + 3.30
Sale price of the 2nd book = 1 u
Total amount that Cody paid
= 1 u + 3.30 + 1 u
= 2 u + 3.30
2 u + 3.30 = 53.70
2 u = 53.70 - 3.30
2 u = 50.40
1 u = 50.40 ÷ 2 = 25.20
Sale price of the 1st book
= 1 u + 3.30
= $28.50
75% of the price = $28.50
100% of the price =
28.5075 x 100 = $38
Selling price of the 1st book before discount = $38
Answer(s): (a) $8.15; (b) $38