A) \[5/7\]
B) \[5/13\]
C) \[1/3\]
D) \[1/2\]
Correct Answer: A
Solution :
Given that, \[P(A)=0.3\] and \[P(A\cup B)=0.8\] We know \[P(A\cup B)=P(A)+P(B)-P(A\cap B)\] \[\Rightarrow \] \[0.8=0.3+P(B)-0.3P\,(B)\] \[[\because \,\,P(A\cap B)=P(A)\,\,P(B)\,\,given]\] \[\Rightarrow \] \[0.5=0.7\,\,P\,(B)\] \[\Rightarrow \] \[P\,(B)=\frac{5}{7}\]You need to login to perform this action.
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