Question 1141770:  Given P(A)=0.23, P(B)=0.61, and P(A∩B)=0.18, what is P(A^c ∩B^c) 
 Answer by ikleyn(52903)      (Show Source): 
You can  put this solution on YOUR website! . 
Let us determine first what is the set  (A^c ∩ B^c).
It is the set of elements of the universal set that belong  NEITHER  "A"  NOR  "B".
In other words, it is the set  ((A U B)^c).
Therefore,  P(A^c ∩ B^c) = P((A U B)^c) = (it is the COMPLEMENT to P(A U B) ) = 1 - P(A U B).
Hence, to answer the problem's question, we need to find  P(A U B)  and then to take the complement to it.
Calculation of  P(A U B) is easy: it is
    P(A U B) = P(A) + P(B) - P(A ∩ B) = 0.23 + 0.61 - 0.18 = 0.66.
Therefore,  P(A^c ∩ B^c) = 1 - P(A U B) = 1 - 0.66 = 0.34.     ANSWER
 
 
Completed and solved.
 
 
 
  | 
 
  
 
 |   
 
 |