A bag contains 3 red balls and 5 black balls. A ball is drawn at random from the bag. What is the probability that the ball drawn is :

(i) red?
(ii) not red?

There are \( 3 \ + \ 5 \ = \ 8 \) balls in a bag. Out of these 8 balls, one can be chosen in 8 ways.

\(\therefore \) Total number of elementary events = 8

(i) Since the bag contains 3 red balls, therefore, one red ball can be drawn in 3 ways.

\(\therefore \) Favourable number of elementary events = 3

Hence, P (getting a red ball ) \( = \ \frac{3}{8} \)

(ii) Since the bag contains 5 black balls along with 3 red ball, therefore, one black (not red) ball can be drawn in 5 ways.

\(\therefore \) , Favourable number of elementary events = 5

Hence, P(not getting a red ball) \( = \ \frac{5}{8} \)