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put this solution on YOUR website!Let V be the speed of his going to the fair, then his speed of the return trip
was 2V.
Now the total distance of the round trip is 2*4 = 8 miles.
By Speed = Distance / Time , and so Time = Distance /SPeed,
we have 3 = 8/V + 8/(2V),
Cancel the denominator by multiple by 2, 6V = 16 + 8 = 24.
so, V =4 and 2V = 8.
Hence, his speed going to the fair was 4 miles/hr,and
his speed backing home was 8 miles/hr.