We know, when a pair of dice is thrown, total possible outcomes are = 36

A=No of outcomes for getting sum of 8 or more are

{(2,6),(3,5),(3,6),(4,4),(4,5),(4,6),(5,3),(5,4),(5,5),(5,6),(6,2),(6,3),(6,4),(6,5),(6,6)} = 15

Therefore, P(A) =

B= No of outcomes for first die showing 4 =

{(4,1),(4,2),(4,3),(4,4),(4,5),(4,6)} = 6

Hence P(B) =

(A B) = outcomes of getting sum as 8 or more with a first die showing 4

= {(4,4),(4,5),(4,6)} = 3

Hence P(A B) =

Therefore, = (answer)