⁵₈ of Eric's savings comprised of 20-cent coins and 10-cent coins. Eric used some 20-cent coins to purchase a basketball set. The number of 10-cent coins left was 40% more than the number of 20-cent coins left. Given that Eric had 72 more 10-cent coins than 20-cent coins left in the end, find the amount of money Eric spent on the basketball set.

	20-cent coins	10-cent coins
Before	5x7 = 35 u	3x7 = 21 u
Change	- 20 u
After	5x3 = 15 u	7x3 = 21 u

Fraction of Eric's savings that comprised of 10-cent coins
= 1 - ⁵₈
= ³₈

Number of 10-cents coins in the end in percentage
= 100% + 40%
= 140%

140% = ¹⁴⁰₁₀₀ = ⁷₅

Number of 10-cent coins remains unchanged. Make the number of 10-cent coins the same.  LCM of 3 and 7 is 21.

Number of more 10-cent coins than 20-cent coins
= 21 u - 15 u
= 6 u

6 u = 72

1 u = 72 ÷ 6 = 12

Number of 20-cent coins spent on the basketball set 
= 35 u - 15 u
= 20 u
= 20 x 12
= 240

Amount that Eric spent on the basketball set 
= 240 x 0.2
= $48

Answer(s): $48