A bag contains a black ball, a red ball and a green ball, all the balls are identical in shape and size. A ball is drawn from the bag without looking into it. What is the probability that the ball drawn is:
Not a red ball

$\text{Step-1: Find probability for a not red ball.}$

                 $\text{Red ball =1, Black ball=1, Green ball=1.}$

                 $\text{Total balls in bag=3.}$

                 $\text{Let P be the probability of getting a not red ball.}$

                 $\text{Probability=}\frac{\text{No. of outcomes(Black and Green)}}{\text{Total no. of outcomes}}$

                 $\text{Probability=}\frac{2}{3}$

$\text{Hence, probability of getting red ball is}$ $\frac{2}{3}.$