PSLE A shop is having a book sale.
The 1st book is at 5% discount.
The 2nd book is at 30% discount.
The price of the 2nd book should be equal or lower than the price of the 1st book.
Mary and Bobby each bought two books at the sale.
- Mary's books were priced at $29 and $29. How much less did she pay for the 2nd book than the 1st book?
- Bobby paid a total of $35.15 for his two books. He paid $8.55 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% $29 |
100% $29 |
|
Discount |
- 5% |
- 30% |
|
Sale price |
95% |
70% |
? |
(a)
Selling price of the 1st book
= 95% x 29
=
95100 x 29
= $27.55
Selling price of 2nd book
= 70% x 29
=
70100 x 29
= $20.30
Amount that Mary paid less for the 2nd book than the 1st book
= 27.55 - 20.30
= $7.25
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 5% |
- 30% |
|
Sale price |
95%
|
70%
|
|
Compare 1st book and 2nd book |
1 u + $8.55 |
1 u |
$35.15 |
(b)
Sale price of the 1st book = 1 u + 8.55
Sale price of the 2nd book = 1 u
Total amount that Bobby paid
= 1 u + 8.55 + 1 u
= 2 u + 8.55
2 u + 8.55 = 35.15
2 u = 35.15 - 8.55
2 u = 26.60
1 u = 26.60 ÷ 2 = 13.30
Sale price of the 1st book
= 1 u + 8.55
= $21.85
95% of the price = $21.85
100% of the price =
21.8595 x 100 = $23
Selling price of the 1st book before discount = $23
Answer(s): (a) $7.25; (b) $23