Question

let a and b be mutually exclusive events with the following probabilities.

• p(a) = 0.3
• p(b) = 0.4

what is p(a or b)?
write your answer as a decimal. do not round.

Explanation:

Step1: Recall probability formula

For mutually - exclusive events \(A\) and \(B\), \(P(A\ or\ B)=P(A)+P(B)\).

Step2: Substitute given values

We know \(P(A) = 0.3\) and \(P(B)=0.4\), so \(P(A\ or\ B)=0.3 + 0.4\).

Answer:

0.7