Answer:
The train is twice fast going relative to the man.
Step-by-step explanation:
Consider the provided information.
Let the distance between the train and beginning of bridge is x and length of bridge is y.
A man is on a 1/4 on a bridge. Thus, the 1/4 of y is y/4.
The train is going x distance in time man runs y/4 distance.
Also if the train is going x + y in time man runs the distance 3y/4.
For better understanding refer the figure 1:
So, if train goes x+y-x distance in time man covers the distance 3y/4 - y/4
Now solve 3y/4 - y/4 = 2y/4
The train covers y distance in the time man runs 2y/4 = y/2
That means train covers 2 times of the distance cover by the man or the train goes twice as fast as man.
Hence, train is twice fast going relative to the man.