Question

A and B are two independent witnesses in a case. The probability that A will speak the truth is 3/4; and that of B is 4/5. In what percent of cases are they likely to contradict each other in stating the same fact?

Answer 1

If E is the event of their contradicting each other, then E = (A ⋂ B) ∪ (A ⋂ B) also (A ⋂ B)and (A ⋂ B) are two mutually exclusive events.

Therefore, in 35% of the cases they are likely to contradict each other.