Question

Q1) If A and B are mutually exclusive events and P(A) = 0.2 and P(B) = 0.7, then P(A and B) is

A) .7600

B) .9000

C) .0000

D) .1400

Q2) If A and B are two independent events with P(A) = 0.1535 and P(B) = 0.6429, then P(A ∪ B) is

A) 0.7964

B) 0.0987

C) 0.3070

D) 0.6977

Answer 1

(Q1) right choice is C) .0000

Two events are said to be mutually exclusive when both cannot occur at the same time and   always have a different outcome. Two events A and B are mutually exclusive, the events are called disjoint events.

If A and B are mutually exclusive events then P(A and B)=P(A∩B)=0

(Q2) right choice is D) 0.6977

If A and B are independent events then P(A and B)= P(A∩B)=P(A)P(B)

since A and B are two independent events with P(A) = 0.1535 and P(B) = 0.6429,

then P(A U B) =P(A)+P(B)-P(A∩B)=P(A)+P(B)-P(A)P(B)=0.1535+0.6429-0.1535*0.6429=0.6977