Complementary events are mutually exclusive, but when combined make the entire sample space. The symbol for the complement of event A is A'. Some books will put a bar over the set to indicate its complement. Since complementary events are mutually exclusive, we can use the special addition rule to find its probability.

Are all complementary events mutually exclusive?

Complementary events are mutually exclusive events since they cannot occur at the same time.

Are complementary events disjoint?

Overlapping events are events that have outcomes in common. Complementary events are events whose probability sum adds up to 1 or 100%. ... They are not complementary because the red - top is not included in the two events. They are not disjoint as there is a blue - bottom.