can you please explain question 31 of cat 2006 solved? how you took e=f+5 for end of 3rd day?

Except e and f nothing had new paper published on 5th, As f is already the smallest number, it cant change, but the e will get f+1 value

If you see the total had changed by 4, that 4 should be due to change in e value from e to f+1,

e - (f+1) = 4

e - f - 1 = 4

e = f+5

cheers!!!!!!!!11