From above relationship , Power is inversely proportional to Resistance.
So,More Power less resistance,Less Power high resistance.
25 W bulb has higher resistance .
If P1=50W and P2=25W
on dividing the above two equations we get,
So, Bulb 1 ( 50W) has higher resistence by a factor of 2 or 2 times than bulb with 25W.
P.S. I think if you use pen and paper to solve the above question , It will help you. Good luck