PSLE
A stationery kiosk 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. Zoe's books were priced at $29 and $35. How much less did she pay for the 2nd book than the 1st book? 
2. Japheth paid a total of $49.20 for his two books. He paid $15.40 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% $35	100% $29
Discount	- 5%	- 35%
Sale price	95%	65%	?

(a)
Selling price of the 1st book
= 95% x 35
= ⁹⁵₁₀₀ x 35
= $33.25

Selling price of 2nd book
= 65% x 29
= ⁶⁵₁₀₀ x 29
= $18.85

Amount that Zoe paid less for the 2nd book than the 1st book
= 33.25 - 18.85
= $14.40

	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 + $15.40	1 u	$49.20

(b)
Sale price of the 1st book = 1 u + 15.40
Sale price of the 2nd book = 1 u

Total amount that Japheth paid
= 1 u + 15.40 + 1 u
= 2 u + 15.40

2 u + 15.40 = 49.20
2 u = 49.20 - 15.40
2 u = 33.80

1 u = 33.80 ÷ 2 = 16.90

Sale price of the 1st book
= 1 u + 15.40
= $32.30

95% of the price = $32.30
100% of the price = ^32.30₉₅ x 100 = $34

Selling price of the 1st book before discount = $34

Answer(s): (a) $14.40; (b) $34