PSLE
A stationery kiosk is having a book sale. The 1st book is at 15% 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. Emily's books were priced at $24 and $25. How much did she pay for them?
2. Luis paid a total of $45.60 for his two books. He paid $10.50 more for the 1st book than the 2nd book. What was the price of the 2nd book before discount? 

	1st book	2nd book	Total amount
Original price	100% $25	100% $24
Discount	- 15%	- 35%
Sale price	85%	65%	?

(a)
Selling price of the 1st book
= 85% x 25
= ⁸⁵₁₀₀ x 25
= $21.25

Selling price of 2nd book
= 65% x 24
= ⁶⁵₁₀₀ x 24
= $15.60

Total amount that Emily paid
= 21.25 + 15.60
= $36.85

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 15%	- 35%
Sale price	85%	65%
Compare 1st book and 2nd book	1 u + $10.50	1 u	$45.60

(b)
Sale price of the 1st book = 1 u + 10.50
Sale price of the 2nd book = 1 u

Total amount that Luis paid
= 1 u + 10.50 + 1 u
= 2 u + 10.50

2 u + 10.50 = 45.60
2 u = 45.60 - 10.50
2 u = 35.10

1 u = 35.10 ÷ 2 = 17.55

Sale price of the 2nd book = $17.55

65% of the price = $17.55
100% of the price = ^17.55₆₅ x 100 = $27

Selling price of the 2nd book before discount = $27

Answer(s): (a) $36.85; (b) $27