Solution
For this case we have the following probabilities given
P(C)= 0.039
P(F and C) = 0.004
P(F or C) = 0.548
We have the following total rule of probability:
P(F or C)= P(F) + P(C) -P(F and C)
And replacing we got:
0.548= P(F) + 0.039 - 0.004
Solving for P(F) we got:
P(F)= 0.548-0.039 + 0.004=0.513