The answer is 2, just follow the order of operations
8 am at 0
8:18 at 4.5
8:48 at 7.5 miles ???
18 min = .3 hour
48 min = .8 hour
in first .3 hours speed = 4.5/.3 = 15 mph
in next .5 hours = speed = 3/.5 = 6 mph
average speed for the whole trip = 7.5 miles/.8 hours = 9.375 mph
Is it the absolute value? If so then 1.
