³₅ of Zeph's savings comprised of 10-cent coins and 20-cent coins. Zeph used some 10-cent coins to purchase a frisbee. The number of 20-cent coins left was 50% more than the number of 10-cent coins left. Given that Zeph had 4 more 20-cent coins than 10-cent coins left in the end, find the amount of money Zeph spent on the frisbee.

	10-cent coins	20-cent coins
Before	3x3 = 9 u	2x3 = 6 u
Change	- 5 u
After	2x2 = 4 u	3x2 = 6 u

Fraction of Zeph's savings that comprised of 20-cent coins
= 1 - ³₅
= ²₅

Number of 20-cents coins in the end in percentage
= 100% + 50%
= 150%

150% = ¹⁵⁰₁₀₀ = ³₂

Number of 20-cent coins remains unchanged. Make the number of 20-cent coins the same.  LCM of 2 and 3 is 6.

Number of more 20-cent coins than 10-cent coins
= 6 u - 4 u
= 2 u

2 u = 4

1 u = 4 ÷ 2 = 2

Number of 10-cent coins spent on the frisbee 
= 9 u - 4 u
= 5 u
= 5 x 2
= 10

Amount that Zeph spent on the frisbee 
= 10 x 0.1
= $1

Answer(s): $1