Question

A bag contains 5 black, 7 red and 3 white balls. A ball is drawn from the bag at random. What is the probability that the ball drawn is not black?

• A. 0.0
• B. $\frac{5}{15}$
• C. $\frac{4}{15}$
• D. $\frac{2}{3}$

Answer 1

The correct option is D $\frac{2}{3}$

Let $E_3$ represent the event of not drawing a black ball.
Total number of balls which are not black = 7+3 =10
$\therefore P\left(E_3\right)=\frac{Numberoffavourableoutcomes}{Totalnumberofoutcomes}=\frac{7+3}{15}$
$=\frac{10}{15}=\frac{2}{3}$
Alternatively,
P (Not Black) = 1 – P (Black)
P (Not Black) $=1-\frac{5}{15}=1-\frac{1}{3}=\frac{2}{3}$