Two dice are thrown simultaneously and the sum of the numbers appearing on them is noted. What is the probability that the sum is 7?

Number of possible outcomes when two dice are thrown simultaneously: 6 × 6 = 36
(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)

The possible outcomes =(1,6), (2,5), (3,4), (4,3), (5,2), (6,1)
Hence, number of possible outcomes = 6

Required probability =6/36
= 1/6