Elijah has 5 more 20-cent coins than 10-cent coins. After he used 14 of his 20-cent coins, the total value of 20-cent coins is $2.90 more than the total value of 10-cent coins. How many coins did he have in the end?

	20¢	10¢
Before	1 u + 5	1 u
Change	- 14
After	1 u - 9	1 u

	20¢	10¢
Number	1 u - 9	1 u
Value	20	10
Total value	20 u - 180	10 u

$1 = 100¢
$2.90 = 290¢

Number of 20¢ coins in the end
= 1 u + 5 - 14
= 1 u - 9

Total value of 20¢ coins in the end
= 20 x (1 u - 9)
= 20 u - 180

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

After using 14 20-cent coins, the value of 20-cent coins is 290¢ more than the value of 10-cent coins. If another 290¢ is added to the 10-cent coins, the total value of 20-cent coins and 10-cent coins will be the same.

20 u - 180 = 10 u + 290
20 u - 10 u = 290 + 180
10 u = 470

1 u = 470 ÷ 10 = 47

Number of coins that Elijah had in the end
= 1 u + 1 u - 9
= 2 u - 9
= (2 x 47) - 9
= 94 - 9
= 85

Answer(s): 85