Xavier has 6 more 20-cent coins than 5-cent coins. After he used 19 of his 20-cent coins, the total value of 20-cent coins is $2.50 more than the total value of 5-cent coins. How many coins did he have in the end?

	20¢	5¢
Before	1 u + 6	1 u
Change	- 19
After	1 u - 13	1 u

	20¢	5¢
Number	1 u - 13	1 u
Value	20	5
Total value	20 u - 260	5 u

$1 = 100¢
$2.50 = 250¢

Number of 20¢ coins in the end
= 1 u + 6 - 19
= 1 u - 13

Total value of 20¢ coins in the end
= 20 x (1 u - 13)
= 20 u - 260

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

After using 19 20-cent coins, the value of 20-cent coins is 250¢ more than the value of 5-cent coins. If another 250¢ is added to the 5-cent coins, the total value of 20-cent coins and 5-cent coins will be the same.

20 u - 260 = 5 u + 250
20 u - 5 u = 250 + 260
15 u = 510

1 u = 510 ÷ 15 = 34

Number of coins that Xavier had in the end
= 1 u + 1 u - 13
= 2 u - 13
= (2 x 34) - 13
= 68 - 13
= 55

Answer(s): 55