Answer :
Answer: 8 hours.
Step-by-step explanation:
We have the relation:
Time = distance/velocity
Distance = 50 miles
Velocity in horse = 9mph
Velocity walking = 3 1/2 mph = 3.5 mph
Then, if T is the total time, X is the distance that he travels in horse and Y is the distance that he travels by foot, we have:
X + Y = 50 miles:
T/2 = X/9mph
T/2 = Y/3.5mph
Then we have:
X/9mph = Y/3.5mph
X = Y*(9/3.5)
And by the first relation:
X = 50 mi - Y
then we have:
50mi - Y = Y*(9/3.5)
50mi = Y + Y*(9/3.5) = Y*(1 + 9/3.5) = Y*3.57
Y = 50mi/3.57 = 14mi
Then we have:
T/2 = 14mi/3.5mph
T = 2*(14/3.5) hours = 8 hours