PSLE A book shop is having a book sale.
The 1st book is at 10% 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.
Xuan and Ethan each bought two books at the sale.
- Xuan's books were priced at $14 and $17. How much less did she pay for the 2nd book than the 1st book?
- Ethan paid a total of $54.35 for his two books. He paid $5.05 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% $17 |
100% $14 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 17
=
90100 x 17
= $15.30
Selling price of 2nd book
= 85% x 14
=
85100 x 14
= $11.90
Amount that Xuan paid less for the 2nd book than the 1st book
= 15.30 - 11.90
= $3.40
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $5.05 |
1 u |
$54.35 |
(b)
Sale price of the 1st book = 1 u + 5.05
Sale price of the 2nd book = 1 u
Total amount that Ethan paid
= 1 u + 5.05 + 1 u
= 2 u + 5.05
2 u + 5.05 = 54.35
2 u = 54.35 - 5.05
2 u = 49.30
1 u = 49.30 ÷ 2 = 24.65
Sale price of the 1st book
= 1 u + 5.05
= $29.70
90% of the price = $29.70
100% of the price =
29.7090 x 100 = $33
Selling price of the 1st book before discount = $33
Answer(s): (a) $3.40; (b) $33