Question

A bag contains $4$ white, $3$ red and $4$ green balls, A ball is drawn at random. Find the probability of the event 'the ball drawn is white or green'.

• A. $\frac{5}{11}$
• B. $\frac{6}{11}$
• C. $\frac{7}{11}$
• D. $\frac{8}{11}$

Answer 1

Answer: (D)

$\frac{8}{11}$

Let $A$ be the event 'the ball drawn is white' and $B$ be the event 'the ball drawn is green'.
$P$(The ball drawn is white or green)$P(A\cup B)=P\left(A\right)+P\left(B\right)-P(A\cap B)=\frac{8}{11}$