PSLE A bookstore is having a book sale. The 1st book is at 5% 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's books were priced at $21 and $35. How much more did she pay for the 1st book than the 2nd book?
- Tom paid a total of $56.10 for his two books. He paid $8.50 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% $35 |
100% $21 |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95% |
85% |
? |
(a)
Selling price of the 1st book
= 95% x 35
=
95100 x 35
= $33.25
Selling price of 2nd book
= 85% x 21
=
85100 x 21
= $17.85
Amount that Min paid more for the 1st book than the 2nd book
= 33.25 - 17.85
= $15.40
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 15% |
|
Sale price |
95%
|
85%
|
|
Compare 1st book and 2nd book |
1 u + $8.50 |
1 u |
$56.10 |
(b)
Sale price of the 1st book = 1 u + 8.50
Sale price of the 2nd book = 1 u
Total amount that Tom paid
= 1 u + 8.50 + 1 u
= 2 u + 8.50
2 u + 8.50 = 56.10
2 u = 56.10 - 8.50
2 u = 47.60
1 u = 47.60 ÷ 2 = 23.80
Sale price of the 1st book
= 1 u + 8.50
= $32.30
95% of the price = $32.30
100% of the price =
32.3095 x 100 = $34
Selling price of the 1st book before discount = $34
Answer(s): (a) $15.40; (b) $34