A sample space consists of a elementary outcomes $e_1,e_2........e_9$ whose probabilities are $P(e_1)=P(e_2)=0.08,P(e_3)=P(e_4)=P(e_5)=.1,P(e_6)=P(e_7)=.2,P(e_8)=p(e_9)=0.07$.Suppose $A=\{e_1,e_5,e_8\},B=\{e_2,e_5,e_8,e_9\}$.Using the addition law of probability ,calculate $P(A \cup B)$ .

Question

$\begin{array}{1 1}(A)\;0.40\\(B)\;0.50\\(C)\;0.60\\(D)\;0.70\end{array}$