Suppose the probability that a student plays basketball is B and student plays football be F.
Thus:
Probability that student plays basketball given that he plays football will be:
P(BIF)=[P(F and B)]/P(F)
P(F)=0.18
P(B)=0.32
hence:
P(BIF)=(0.32×0.18)/0.18
=0.0576/0.18
=0.32