A dice rolling just once
What is probability of given the face is odd, it is a 1?
A= event that odd will occur
B= event that 1 is the outcome
then p(B|A)=p(A and B)/p(A)=(1/3)/(3/6)=2/3[p(A and B)=1/3 since out of three odds 1,3,5 ,the 1 is the only one possible case]