When two dice are rolled together, then total outcomes are 36 and sample space is
‌[(1,1),(1,2),(1,3),(1,4),(1,5),(1,6),
‌(2,1),(2,2),(2,3),(2,4),(2,5),(2,6),
‌(3,1),(3,2),(3,3),(3,4),(3,5),(3,6),
‌(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)]
So, pairs with sum 9 are
(3,6)(4,5),(5,4),(6,3) i.e total 4 pairs.
Total outcomes
=36Favourable outcomes
=4Probability of getting the sum of 9
=‌=‌