(i) a red ball?

(ii) not a red ball?

Solution:

The total number of balls inside the bag = Number of red balls + Number of black balls

So, the total no. of balls inside the bag = 5+3 = 8

As we know that the probability of an event is the ratio between the number of favourable outcomes and the total number of outcomes.

P(E) = (Number of favourable outcomes/ Total number of outcomes)

(i) Probability of picking up a red ball = P (red balls) = (number of red balls/total number of balls) = 3/8

(ii) Probability of picking up a black ball = P (black balls) = (number of black balls/total number of balls) = 5/8