Throw 2 dices simultaneously. What is the probability that the summation of the numbers is multiply of 4?
Solution:
All possibilities are:
(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)
Let A be the event "sum is multiply of 4". A contains (2,2), (1,3), (3,1), (2,6), (6,2), (3,5), (5,3), (4,4), (6,6); so P(A) = 9/36=1/4