Question

section 5.2 homework
score 4/15 answered 4/15
question 5
find the indicated probability
given
p(a) = 0.25
p(a or b) = 0.65
p(a and b) = 0.2
find
p(b) =
are these events disjoint?
yes
no

Explanation:

Step1: Use the formula for the probability of the union of two events

$P(A\ or\ B)=P(A)+P(B)-P(A\ and\ B)$

Step2: Rearrange the formula to solve for $P(B)$

$P(B)=P(A\ or\ B)-P(A)+P(A\ and\ B)$

Step3: Substitute the given values

$P(B)=0.85 - 0.25+0.2$
$P(B)=0.8$

Answer:

$0.8$