Skip to main contentSkip to solution

If A and B are event such that P(A)=12P(A)=\dfrac{1}{2}, P(B)=pP(B)=p and P(A∪B)=35P(A \cup B)=\dfrac{3}{5} then which of following statements is/are TRUE?

(A) Events A and B are independent if p=15p=\dfrac{1}{5}

(B) Events A and B are independent if p∈(0,1)∼{15}p \in (0,1) \sim \left\{\dfrac{1}{5}\right\}

(C) Events A and B are independent then P(A∩B)=110P(A \cap B)=\dfrac{1}{10}

(D) Event A and B are independent then P(A∩B)=910P(A \cap B)=\dfrac{9}{10}

Choose the correct answer from the options given below:

Solution

✅ Correct Option: 3

If AA and BB are independent, P(A∩B)=p2P(A\cap B) = \dfrac{p}{2}.

Then 35=12+p−p2\dfrac{3}{5} = \dfrac{1}{2} + p - \dfrac{p}{2}, giving p2=110\dfrac{p}{2} = \dfrac{1}{10}, so p=15p = \dfrac{1}{5} and P(A∩B)=110P(A\cap B) = \dfrac{1}{10}.

So (A) and (C) hold, while (B) and (D) fail.

Keyboard Shortcuts

  • Left arrow: Previous question
  • Right arrow: Next question
  • S key: Jump to solution
  • Q key: Jump to question