It will take you 30 minutes to drive 40 miles.
Here's the solution using the distance formula:
d = rt
d = distance, r = rate (or speed) and t = time
In this word problem, you would substitute in as follows: 40 miles = 80mpht.
40 = 80t
40/80 = t
0.5 = t
t = 0.5 hours or 30 minutes
Tip! Learn more about the three basic aspects of movement and travel: distance, rate and time at Gcflearnfree.org.