⁷₁₀ of Seth's savings comprised of 20-cent coins and 50-cent coins. Seth used some 20-cent coins to purchase a basketball set. The number of 50-cent coins left was 40% more than the number of 20-cent coins left. Given that Seth had 60 more 50-cent coins than 20-cent coins left in the end, find the amount of money Seth spent on the basketball set.

	20-cent coins	50-cent coins
Before	7x7 = 49 u	3x7 = 21 u
Change	- 34 u
After	5x3 = 15 u	7x3 = 21 u

Fraction of Seth's savings that comprised of 50-cent coins
= 1 - ⁷₁₀
= ³₁₀

Number of 50-cents coins in the end in percentage
= 100% + 40%
= 140%

140% = ¹⁴⁰₁₀₀ = ⁷₅

Number of 50-cent coins remains unchanged. Make the number of 50-cent coins the same.  LCM of 3 and 7 is 21.

Number of more 50-cent coins than 20-cent coins
= 21 u - 15 u
= 6 u

6 u = 60

1 u = 60 ÷ 6 = 10

Number of 20-cent coins spent on the basketball set 
= 49 u - 15 u
= 34 u
= 34 x 10
= 340

Amount that Seth spent on the basketball set 
= 340 x 0.2
= $68

Answer(s): $68