Probability

If $A$ and $B$ are mutually exclusive events and $P\left(A\right) = 0.28$, $P \left(B\right)=0.44$, then find

  1. $P \left(\overline{A}\right)$
  2. $P \left(A \cup B\right)$
  3. $P \left(A \cap \overline{B}\right)$
  4. $P \left(\overline{A} \cap \overline{B}\right)$


$\because \;$ $A$ and $B$ are mutually exclusive events, $A \cap B = 0$

  1. $P \left(\overline{A}\right) = 1 - P \left(A\right) = 1 - 0.28 = 0.72$


  2. $P \left(A \cup B\right) = P \left(A\right) + P \left(B\right) - P \left(A \cap B\right) = P \left(A\right) + P \left(B\right)$

    i.e. $\;$ $P \left(A \cup B\right) = = 0.28 + 0.44 = 0.72 $


  3. $P \left(A \cap \overline{B}\right) = P \left(A\right) - P \left(A \cap B\right) = P \left(A\right) = 0.28$


  4. $P \left(\overline{A} \cap \overline{B}\right) = P \left(\overline{A \cup B}\right) = 1 - P \left(A \cup B\right) = 1 - 0.72 = 0.28$