Final answer:
The auto mechanic would charge a total of $450 for 10 hours of work, calculated by adding the initial fee of $50 to the hourly rate of $40 multiplied by 10 hours.
Step-by-step explanation:
The auto mechanic charges an initial fee of $50, and then an additional $40 per hour. To calculate the total charge for 10 hours of work, we use the equation C = 50 + 40h, where C represents the total charge and h represents the hours worked.
Substituting 10 hours into the equation, we get:
C = 50 + 40(10)
C = 50 + 400
C = $450
Therefore, the mechanic will charge $450 for 10 hours of work in one day.