³₅ of Fred's savings comprised of 20-cent coins and 10-cent coins. Fred used some 20-cent coins to purchase a doll set. The number of 10-cent coins left was 50% more than the number of 20-cent coins left. Given that Fred had 8 more 10-cent coins than 20-cent coins left in the end, find the amount of money Fred spent on the doll set.

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

Fraction of Fred's savings that comprised of 10-cent coins
= 1 - ³₅
= ²₅

Number of 10-cents coins in the end in percentage
= 100% + 50%
= 150%

150% = ¹⁵⁰₁₀₀ = ³₂

Number of 10-cent coins remains unchanged. Make the number of 10-cent coins the same.  LCM of 2 and 3 is 6.

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

2 u = 8

1 u = 8 ÷ 2 = 4

Number of 20-cent coins spent on the doll set 
= 9 u - 4 u
= 5 u
= 5 x 4
= 20

Amount that Fred spent on the doll set 
= 20 x 0.2
= $4

Answer(s): $4