Question

Let A and B be two events. Suppose P(A) = 0.4, P(B) = P, and $P (A \cup B) = 0 .7$ . The value of p for which A and B are independent is

Moderate

Solution

$P (A \cup B) = P (A) + P (B) - P (A) \times P (B)$
$\Rightarrow 0 .7 = 0 .4 + p - 0 .4 p$
$∴ 0 .6 p = 0 .3 or p = \frac{1}{2}$

Get Instant Solutions

When in doubt download our app. Now available Google Play Store- Doubts App

Recieve an sms with download link

SCAN ME