Question

Mark the correct alternative in the following question:

If A and B are two events such that P(A) = \[\frac{4}{5}\] , and \[P\left( A \cap B \right) = \frac{7}{10}\] , then P(B|A) =

पर्याय

•  `1/10`

• `1/8`

•  `7/8`

•  `17/20`

Answer 1

 We have ,
\[P\left( A \right) = \frac{4}{5} \text{ and }  P\left( A \cap B \right) = \frac{7}{10}\]
\[\text{ Now } , \]
\[P\left( B|A \right) = \frac{P\left( A \cap B \right)}{P\left( A \right)}\]
\[ = \frac{\left( \frac{7}{10} \right)}{\left( \frac{4}{5} \right)}\]
\[ = \frac{7 \times 5}{10 \times 4}\]
\[ = \frac{7}{8}\]