Question

A bag contains 4 red, 5 black and 6 white balls. A ball is drawn from the bag at random. Find the probability that the ball drawn is :

(a) white

(b) red

(c) not black

(d) red or white

Answer 1

GIVEN: A bag contains 4 red, 5 black and 6white balls and a ball is drawn at random

TO FIND: Probability of getting a

(i) white ball

(ii) red ball

(iii) not black ball

(iv) red or white

Total number of balls

(i) Total number white balls are 6

We know that PROBABILITY =

Hence probability of getting white a ball is

(ii) Total number of red are 4

We know that PROBABILITY =

Hence probability of getting red a ball is equal to

(iii) Total number of black balls are 5

We know that PROBABILITY =

Hence probability of getting black ball

We know that sum of probability of occurrence of an event and probability of non occurrence of an event is 1.

Hence the probability of getting non black ball is

(iv) Total number of red or white balls is

We know that PROBABILITY =

Hence probability of getting white or red ball