A set of stamps costs 3 one-dollar bills, 3 dimes and 2 pennies. After buying this set of stamp, Henry had $3.48 left. How much money did he have at first?

$

3 one-dollar bills = $3

3 dimes = 3 × 10 = 30¢ = $0.30

2 pennies = 2¢ = $0.02

3 + 0.30 + 0.02 = $3.32

3.48 + 3.32 = $6.80