Answer: $2.05
Explanation:
Add all values of what he spent: 6.65 + 0.75 + 0.75 + 1.30 = 9.45
Total spent is $9.45
Next you need to subtract that from what he started with: 15 - 9.45 = 5.55 then subtract what he had left 5.55 - 3.50 = 2.05, so he had to have spent $2.05 on the bus ride