I am not sure if I am right, but this is the best I can answer.
Useing reason, and logic, my guess would be if you take 125, and divided it by 4, you would get 31.25. that should be the answer... if i am wrong, i am truely sorry. I havent been in the subject in a while...
You would multiply the cups of flour by 3 and the cups of water by 3. which would give you 9 cups of flour and 6 cups of water. the ratio is 1.5 cups of flour to 1 cup of water.