According to my calculation the answer is B ( Assuming fill rate is cubic meters per hour ). Below is the solution:
Pond A current volume (VA) = 200
Pond B current volume (VB)= 122
Pond A fill rate (RA)= x
Pond B fill rate (RB)= x + 22
Pond A volume at time t= Pond B volume at time t
VA + RA*t= VB + RB*t
200 + x*t = 112 + (x + 22)*t
88 + x*t = x*t + 22*t
88 = 22*t
4 = t
Please note units are same so have omitted that in the answer. Let me know if the solution is correct.
Absolutely correct, thanks