Answer:
It will take 0.75B hours for the return leg
Step-by-step explanation:
Here, given that the first leg of the trip was for B hours at 3 miles per hour , we want to calculate the number of hours the return leg will take at 4 miles per hour given that it is the same distance.
Mathematically, we know that ;
Distance = speed * time
So the distance taken on the first leg of the trip would be;
Distance = 3 miles per hour * B hours = 3B miles
Now, this distance was traveled on the return leg also.
This means that the time taken here will be;
Time on return leg = distance/speed = 3B/4 = 0.75B hours