Answer: $54.12
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Step-by-step explanation:
If his father saves 18%, then he pays the remaining 82% since 100-18 = 82.
The 82% then converts to 0.82 which is one of the multipliers we'll use to get the answer.
The other multiplier is 1.10 to represent an increase of 10%
The net multiplier is 0.82*1.10 = 0.902
Therefore, his father pays 0.902*60 = 54.12 dollars after the discount and maintenance fee are applied.