Xuan spent ¹₇ of her money on some punchers. She spent ¹₆ of the remaining money on some rulers and ³₅ of what was left on some post-it pads.

1. What fraction of her money was spent on post-it pads?
2. Given that the punchers cost $20 less than the post-it pads, find the sum of money that Xuan spent.

Punchers	Remaining money
1	6
	Rulers	Left
	1	5
		Post-it Pads	Rest
1 u	1 u	3 u	2 u

(a)
Fraction of money left after spending on the punchers
= 1 - ¹₇
= ⁶₇

Fraction of remaining money after spending on the rulers
= 1 - ¹₆
= ⁵₆

Fraction of what was left after spending on the post-it pads
= 1 - ³₅
= ²₅

Fraction of money that was spent on post-it pads = ³₇

(b)
Amount that Xuan spent on the punchers = 1 u
Amount that Xuan spent on the post-it pads = 3 u

Amount that the punchers cost less than the post-it pads
= 3 u - 1 u
= 2 u

2 u = 20

1 u = 20 ÷ 2 = 10

Amount that Xuan sent
= 1 u + 1 u + 3 u
= 5 u
= 5 x 10
= $50

Answer(s): (a) ³₇; (b) $50