A bag contains $3$ red balls, $5$ black balls and $4$ white balls. if A ball is drawn at random from the bag. Then What is the probability that the ball drawn is:(iii) black? (iv) not red

(iii) Total number of black balls is $5$

As We know that, Probability = Number of favorable outcomes/ Total number of outcomes

Therefore, the probability of getting a black ball $=5/12$

(iv) Total number of balls which are not red are $4$ white balls and $5$ black balls i.e. $4+5=9$

As We know that, Probability = Number of favorable outcomes/ Total number of outcomes

Therefore, the probability of getting no red ball $=9/12=3/2$