Two dice are thrown. The events A, B and C are as follows:
A: getting an even number on the first die.
B: getting an odd number on the first die.
C: getting the sum of the numbers on the dice ≤ 5
State whether the following is true or false (give reason for your answer):
A and B' are mutually exclusive.
Two dice are rolled:
S = {(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)} ...(I)
A: Getting an even number on the first die.
A = {(2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (4,1), (4,2), (4,3), (4,4),
(4, 5), (4,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6)} ...(II)
B: Getting an odd number on the first die.
B = {(1,1), (1,2), (1,3), (1,4), (1,5), (1,6), (3,1), (3,2), (3,3), (3,4),
(3,5), (3,6), (5,1), (5,2), (5,3), (5,4), (5,5), (5,6)} ...(III)
C: Getting a sum on the two dice.
C = {(1,1), (1,2), (1,3), (1,4), (2,1), (2,2), (2,3), (3,1), (3,2), (4,1) ...(IV)
From (I) and (III)
B' = S - B
= {(2,1), (2,2), (2,3), (2,4), (2,5), (2,6), (4,1), (4,2), (4,3), (4,4),
(4, 5), (4,6), (6,1), (6,2), (6,3), (6,4), (6,5), (6,6)}
= A [By using part (iii)]
∴ A and B' are not mutually exclusive.
Hence, the statement is false.