PSLE A 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.
Lynn and Paul each bought two books at the sale.
- Lynn's books were priced at $18 and $28. How much more did she pay for the 1st book than the 2nd book?
- Paul paid a total of $47.45 for his two books. He paid $8.35 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% $28 |
100% $18 |
|
Discount |
- 10% |
- 15% |
|
Sale price |
90% |
85% |
? |
(a)
Selling price of the 1st book
= 90% x 28
=
90100 x 28
= $25.20
Selling price of 2nd book
= 85% x 18
=
85100 x 18
= $15.30
Amount that Lynn paid more for the 1st book than the 2nd book
= 25.20 - 15.30
= $9.90
|
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 + $8.35 |
1 u |
$47.45 |
(b)
Sale price of the 1st book = 1 u + 8.35
Sale price of the 2nd book = 1 u
Total amount that Paul paid
= 1 u + 8.35 + 1 u
= 2 u + 8.35
2 u + 8.35 = 47.45
2 u = 47.45 - 8.35
2 u = 39.10
1 u = 39.10 ÷ 2 = 19.55
Sale price of the 1st book
= 1 u + 8.35
= $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) $9.90; (b) $31