Answer: A. 56 miles.
Step-by-step explanation:
Formula,
Total rent for car = Fixed rate + (Additional rate per mile) x (Number of mile)
Let x be the number of miles droven .
As per given ,
A car rental company charges $34 per day for a rented car and $0.50 for every mile driven.
i.e. Total rent for car = 34 +0.5x ...(i)
A second rental company charges $20 per day and $0.75 for every mile driven.
i.e. Total rent for car = 20 +0.75x ...(ii)
If both company charges the same , then from (i ) and (ii) , we have

Hence, the number of miles at which both companies charge the same amount for a one-day rental = 56 miles
Thus, the correct answer is A. 56 miles.