PSLE A book shop is having a book sale. The 1st book is at 25% discount. The 2nd book is at 35% discount. The price of the 2nd book should be equal or lower than the price of the 1st book.
- Betty's books were priced at $21 and $25. How much did she pay for them?
- Nick paid a total of $33.15 for his two books. He paid $5.85 less for the 2nd book than the 1st book. What was the price of the 2nd book before discount?
|
1st book |
2nd book |
Total amount |
Original price
|
100% $25 |
100% $21 |
|
Discount |
- 25% |
- 35% |
|
Sale price |
75% |
65% |
? |
(a)
Selling price of the 1st book
= 75% x 25
=
75100 x 25
= $18.75
Selling price of 2nd book
= 65% x 21
=
65100 x 21
= $13.65
Total amount that Betty paid
= 18.75 + 13.65
= $32.40
|
1st book |
2nd book |
Total amount |
Original price |
100% |
100% |
|
Discount |
- 25% |
- 35% |
|
Sale price |
75%
|
65%
|
|
Compare 1st book and 2nd book |
1 u + $5.85 |
1 u |
$33.15 |
(b)
Sale price of the 1st book = 1 u + 5.85
Sale price of the 2nd book = 1 u
Total amount that Nick paid
= 1 u + 5.85 + 1 u
= 2 u + 5.85
2 u + 5.85 = 33.15
2 u = 33.15 - 5.85
2 u = 27.30
1 u = 27.30 ÷ 2 = 13.65
Sale price of the 2nd book = $13.65
65% of the price = $13.65
100% of the price =
13.6565 x 100 = $21
Selling price of the 2nd book before discount = $21
Answer(s): (a) $32.40; (b) $21