PSLE
A store is having a book sale. The 1st book is at 5% 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. Emma's books were priced at $28 and $33. How much did she pay for them?
2. Simon paid a total of $27.10 for his two books. He paid $12.80 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% $33	100% $28
Discount	- 5%	- 35%
Sale price	95%	65%	?

(a)
Selling price of the 1st book
= 95% x 33
= ⁹⁵₁₀₀ x 33
= $31.35

Selling price of 2nd book
= 65% x 28
= ⁶⁵₁₀₀ x 28
= $18.20

Total amount that Emma paid
= 31.35 + 18.20
= $49.55

	1st book	2nd book	Total amount
Original price	100%	100%
Discount	- 5%	- 35%
Sale price	95%	65%
Compare 1st book and 2nd book	1 u + $12.80	1 u	$27.10

(b)
Sale price of the 1st book = 1 u + 12.80
Sale price of the 2nd book = 1 u

Total amount that Simon paid
= 1 u + 12.80 + 1 u
= 2 u + 12.80

2 u + 12.80 = 27.10
2 u = 27.10 - 12.80
2 u = 14.30

1 u = 14.30 ÷ 2 = 7.15

Sale price of the 2nd book = $7.15

65% of the price = $7.15
100% of the price = ^7.15₆₅ x 100 = $11

Selling price of the 2nd book before discount = $11

Answer(s): (a) $49.55; (b) $11