Explanation:
rate=distance/time
Then time= distance/rate
Let rate of walking be = x miles/hr
Then, rate of trotting = (x+3) miles/hr
During an equal duration
trotting distance=8 miles
walking distance= 5 miles
Since the time in both cases are the same
trotting time = walking time
8 / (x+3) = 5 / x
8x = 5x+15
8x-5x = 15
3x = 15
x = 5
Since x = 5,
walking time= 5/5
=1 hour
then trotting time is also = 1 hour