Answer:
For Garage A, the total cost to park for t hours is:
A(t) = 12 + 4t
For Garage B, the total cost to park for t hours is:
B(t) = 8 + 6t
To find the interval of hours parked for which Garage A is cheaper than Garage B, we can set A(t) < B(t) and solve for t:
12 + 4t < 8 + 6t
4t - 6t < 8 - 12
-2t < -4
t > 2
Therefore, Garage A is cheaper than Garage B for any time parked greater than 2 hours.