Sam has 6 more 10-cent coins than 5-cent coins. After he used 20 of his 10-cent coins, the total value of 10-cent coins is $2.30 more than the total value of 5-cent coins. How many coins did he have at first?

	10¢	5¢
Before	1 u + 6	1 u
Change	- 20
After	1 u - 14	1 u

	10¢	5¢
Number	1 u - 14	1 u
Value	10	5
Total value	10 u - 140	5 u

$1 = 100¢
$2.30 = 230¢

Number of 10¢ coins in the end
= 1 u + 6 - 20
= 1 u - 14

Total value of 10¢ coins in the end
= 10 x (1 u - 14)
= 10 u - 140

Total value of 5¢ coins in the end
= 5 x 1 u
= 5 u

After using 20 10-cent coins, the value of 10-cent coins is 230¢ more than the value of 5-cent coins. If another 230¢ is added to the 5-cent coins, the total value of 10-cent coins and 5-cent coins will be the same.

10 u - 140 = 5 u + 230
10 u - 5 u = 230 + 140
5 u = 370

1 u = 370 ÷ 5 = 74

Number of coins that Sam had at first
= 1 u + 1 u + 6
= 2 u + 6
= (2 x 74) + 6
= 148 + 6
= 154

Answer(s): 154