First of all, if the speed mentioned in this question has increased by 0.25, and 0.25 means a specific increase, then this question cannot be done.

If 0.25 refers to 1/4 of the original speed, the steps are as follows.

1, 1=5/4.

Set the time to t, then the return time is (t-5/4).

Because the distance is constant, the speed increases 1/4, and x = vt.

Vt=( 1+ 1/4)V*(t-5/4)

t=( 1+ 1/4)*(t-5/4)

t=25/4

Total round-trip time =25/4+25/4-5/4=45/4.