Answer:
[tex]P(a\ or\ b) = 0.65[/tex]
Step-by-step explanation:
Given
P(a) = 0.60
P(b) = 0.20
P(a and b) = 0.15
Required
Determine P(a or b)
In probability;
[tex]P(a\ and\ b) = P(a) + P(b) - P(a\ or\ b)[/tex]
Substitute values for P(a and b), P(a) and P(b)
[tex]0.15 = 0.60 + 0.20 - P(a\ or\ b)[/tex]
Collect Like Terms
[tex]P(a\ or\ b) = 0.60 + 0.20 - 0.15[/tex]
[tex]P(a\ or\ b) = 0.65[/tex]
Hence, option B answers the question
