Given an unbiased die is tossed twice so the sample space contain 36 elements.

Let A be the probability of getting 4,5,6 on first toss

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

(5,1),(5,2),(5,3),(5,4),(5,5),(5,6),

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

Let B be the probability of getting 1,2,3,4 on the second toss

B={1,1),(1,2),(1,3),(1,4),(2,1),(2,2),(2,3),(2,4),

(3,1),(3,2),(3,3),(3,4),(4,1),(4,2),(4,3),(4,4),(5,1),(5,2),(5,3),(5,4)

(6,1),(6,2),(6,3),(6,4)}

P(getting 4,5,6 on the first toss and 1,2,3 or 4 on the second toss)