The minimum number that Radhas die can show is 1 and 1, which sums up to 2.So. Raja must have his dice show numbers from 3 to 6 including both,When Rajas dice shows 3, Radhas die can show only (1,1). Probability of this happening=When Rajas dice shows 4, Radhas die can show (1,1), (1,2) or (2,1). Probability of this happening=When Rajas dice shows 5, Radhas die can show (1,1), (1,2), (2,1), (2,2), (1,3), (3,1). Probability of this happening=When Rajas dice shows 6, Radhas die can show (1,1), (1,2), (2,1), (2,2), (1,3), (3,1), (3,2), (2,3), (4,1), (1,4). Probability of this happening=.. Required probability=