experiment

Question

Let E and F be two events of an experiment with sample space S.  Suppose P(E) = 0.6,  P(F) = 0.4 and P(E n F)=0.2   Compute

 a. P(E u F) =

         

          c

 b. P(F  ) = 

 

 

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Answer 1

(a)  Use the formula P(A u B) = P(A) + P(B) - P(A n B).  Use E and F in place of A and B, and substitute in known values:

 

P(E u F) = P(E) + P(F) - P(E n F)

=0.6 + 0.4 - 0.2

=0.8

 

(b) Use the forumula P(A^c) = 1 - P(A):

 

P(F^c) = 1 - P(F)

=1 - 0.4

=0.6