Answer:
16 hours
Step-by-step explanation:
Let the mechanic works for x hours to make a money of $350.
Fixed charges = $30
Charges per hour = $20
So, charges for x hours = $20x
Total money earned = $350
[tex] \implies \: 20x + 30 = 350 \\ \\ \implies \: 20x = 350 - 30 \\ \\ \implies \: 20x = 320 \\ \\ \implies \: x = \frac{320}{20} \\ \\ \implies \: x = 16 \: hours[/tex]
Thus, the mechanic needs to work for 16 hours to make $350.
