Question

The probability that student fred sotiropulus takes history 101 next semester is 0.6 and the probability that he takes psychology 101 is also 0.6. what is the probability that he takes at least one of these two courses next semester?

Answer 1

Let the event he takes history be A.
Let the event he takes psychology be B.
$P(A\cup B)=P(A)+P(B)-P(A\cap B)$
$P(A\cup B)=0.6+0.6-0.6^{2}=0.84$
The answer is : 0.84