Answer: 40 minutes
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Work Shown
3/8 = 0.375
7 1/2 = 7 & 1/2 = 7 + 1/2 = 7 + 0.5 = 7.5
Each decimal value is exact without any rounding done to it.
(0.375 miles)/(7.5 minutes) = (2 miles)/(x minutes)
0.375/7.5 = 2/x
0.375x = 7.5*2
0.375x = 15
x = 15/0.375
x = 40 minutes