Suppose S and T are mutually exclusive events. Find P(S or T) if P(S) = 1/3 and P(T) = 5/12?
3/4
7/18
5/36
3/4
7/18
5/36
2 Answers
Apr 20, 2017
In an OR situation you may ADD
Explanation:
Apr 24, 2017
# P(S uu T) = 3/4 #
Explanation:
We use the following fundamental definition from Probability and Set Theory:
# P(A uu B) = P(A) + P(B) - P(A nn B) #
And if we apply this to our problem we have:
# P(S uu T) = P(S) + P(T) - P(S nn T) #
# " " = 1/3 + 5/12 - P(S nn T) #
# " " = 3/4 - P(S nn T) #
Now we are told that
# P(S nn T) =0 #
Hence,
# P(S uu T) = 3/4 #