Question

A bag contains $3$ black, $4$ white and $5$ red balls. One ball is drawn at random. Find the probability that it is either a black ball or red ball.

• A. $\frac{2}{3}$
• B. $\frac{5}{12}$
• C. $\frac{1}{12}$
• D. $\frac{1}{2}$

Answer 1

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

A bag contains 3 black, 4 white and 5 red balls. One ball is drawn at random. Find the probability that it is either a black ball or red ball.

number of red and black ball/(total number of balls)

number of red and black balls$=5+3$

total number of balls $=5+3+4$

$P\left(E\right)=\frac{8}{12}=\frac{2}{3}$