I am giving you my calculation if you find the correct one then please comment on this answer and I will remove it. I WANT THE CORRECT ANSWER IF YOU FIND IT.
Since the maximum tension is 755 N and assuming the initial velocity to be 0
We can write the free body equation as
T - mg = ma where a is the acceleration with which he is being pulled
= 755 - 73×9.81 = 73×a
So a = 0.53 m/s²
Also s = ut + 1/2at² , u = 0 , s = 3.4 m
Solving the above we get t = 3.58 sec
