PSLE
A stationery kiosk 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.

1. Kimberly's books were priced at $14 and $15. How much did she pay for them?
2. Lee paid a total of $29.15 for his two books. He paid $8.35 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% $15	100% $14
Discount	- 25%	- 35%
Sale price	75%	65%	?

(a)
Selling price of the 1st book
= 75% x 15
= ⁷⁵₁₀₀ x 15
= $11.25

Selling price of 2nd book
= 65% x 14
= ⁶⁵₁₀₀ x 14
= $9.10

Total amount that Kimberly paid
= 11.25 + 9.10
= $20.35

	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 + $8.35	1 u	$29.15

(b)
Sale price of the 1st book = 1 u + 8.35
Sale price of the 2nd book = 1 u

Total amount that Lee paid
= 1 u + 8.35 + 1 u
= 2 u + 8.35

2 u + 8.35 = 29.15
2 u = 29.15 - 8.35
2 u = 20.80

1 u = 20.80 ÷ 2 = 10.40

Sale price of the 2nd book = $10.40

65% of the price = $10.40
100% of the price = ^10.40₆₅ x 100 = $16

Selling price of the 2nd book before discount = $16

Answer(s): (a) $20.35; (b) $16