Flynn has 2 more 50-cent coins than 10-cent coins. After he used 12 of his 50-cent coins, the total value of 50-cent coins is $2.60 more than the total value of 10-cent coins. How many coins did he have in the end?

	50¢	10¢
Before	1 u + 2	1 u
Change	- 12
After	1 u - 10	1 u

	50¢	10¢
Number	1 u - 10	1 u
Value	50	10
Total value	50 u - 500	10 u

$1 = 100¢
$2.60 = 260¢

Number of 50¢ coins in the end
= 1 u + 2 - 12
= 1 u - 10

Total value of 50¢ coins in the end
= 50 x (1 u - 10)
= 50 u - 500

Total value of 10¢ coins in the end
= 10 x 1 u
= 10 u

After using 12 50-cent coins, the value of 50-cent coins is 260¢ more than the value of 10-cent coins. If another 260¢ is added to the 10-cent coins, the total value of 50-cent coins and 10-cent coins will be the same.

50 u - 500 = 10 u + 260
50 u - 10 u = 260 + 500
40 u = 760

1 u = 760 ÷ 40 = 19

Number of coins that Flynn had in the end
= 1 u + 1 u - 10
= 2 u - 10
= (2 x 19) - 10
= 38 - 10
= 28

Answer(s): 28