A pair of dice is thrown. Find the probability of getting a sum of at least 9 if 5 appears on at least one of the dice.

Explanation

A pair of dice is thrown. Let A be the event of getting at least 9 point and B, the event that 5 appears on at least one of the dice.
`therefore` B={(1,5),(2,5),(3,5),(4,5),(5,5),(5.6),(5,1),(5,2),(5,3),(5,4),(5,6)}
A={(3,6),(4,5),(5,4),(6,3),(4,6),(5,5),(6,4),(5,6),(6,5),(6,6)}`therefore A capB`={(4,5),(5,4),(5,5),(5,6),(6,5)
`thereforeP(A|B)=P((A capB))/(P(B))=(5/36)/(11/36)=5/11`