PSLE A stationery 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.
Min and Elijah each bought two books at the sale.
- Min's books were priced at $5 and $17. How much less did she pay for the 2nd book than the 1st book?
- Elijah paid a total of $38.75 for his two books. He paid $9.85 less for the 2nd book than for the 1st book. What was the price of the 1st book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $17 |
100% $5 |
|
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 5
=
85100 x 5
= $4.25
Amount that Min paid less for the 2nd book than the 1st book
= 15.30 - 4.25
= $11.05
|
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 + $9.85 |
1 u |
$38.75 |
(b)
Sale price of the 1st book = 1 u + 9.85
Sale price of the 2nd book = 1 u
Total amount that Elijah paid
= 1 u + 9.85 + 1 u
= 2 u + 9.85
2 u + 9.85 = 38.75
2 u = 38.75 - 9.85
2 u = 28.90
1 u = 28.90 ÷ 2 = 14.45
Sale price of the 1st book
= 1 u + 9.85
= $24.30
90% of the price = $24.30
100% of the price =
24.3090 x 100 = $27
Selling price of the 1st book before discount = $27
Answer(s): (a) $11.05; (b) $27