PSLE A stationery kiosk 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.
Olivia and Henry each bought two books at the sale.
- Olivia's books were priced at $2 and $16. How much more did she pay for the 1st book than the 2nd book?
- Henry paid a total of $51.70 for his two books. He paid $4.10 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% $16 |
100% $2 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 16
=
90100 x 16
= $14.40
Selling price of 2nd book
= 85% x 2
=
85100 x 2
= $1.70
Amount that Olivia paid more for the 1st book than the 2nd book
= 14.40 - 1.70
= $12.70
|
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 + $4.10 |
1 u |
$51.70 |
(b)
Sale price of the 1st book = 1 u + 4.10
Sale price of the 2nd book = 1 u
Total amount that Henry paid
= 1 u + 4.10 + 1 u
= 2 u + 4.10
2 u + 4.10 = 51.70
2 u = 51.70 - 4.10
2 u = 47.60
1 u = 47.60 ÷ 2 = 23.80
Sale price of the 1st book
= 1 u + 4.10
= $27.90
90% of the price = $27.90
100% of the price =
27.9090 x 100 = $31
Selling price of the 1st book before discount = $31
Answer(s): (a) $12.70; (b) $31