Question

If two events are complementary , then the sum of their probabilities is

a) 0.
b) 0.25.
c) 0.5.
d) 1.

Answer 1

When two event are complementary than the sum of their probabilities is 1 or 100%.
For instance: there is a 60% chance that it will rain so there is a 40% chance that it will not rain. .6 + .4 = 1

Answer 2

I think the answer would be D. 1