Answer:
The car must be parked there for 5 days
Explanation:
Let the number of days be x
For x days, the amount paid would be 10 + 2(x ) = 10 + 2x
now this amount is equal to an average value of $4 per day for same x days. Using the average , the amount of money paid will be $4x
Now since these two values are equal, we equate them
10 + 2x = 4x
10 = 4x - 2x
2x = 10
x = 10/2 = 5 days