(Q1) A box contains 3 blue, 2 white, and 4 red marbles. If a marble is selected at random from the box, what is the probability that it will be

(i)White ?   (ii)Blue ?   (iii)Red ?

Solution :

Saying that a marble is drawn at random means all the marbles are equally likely to be drawn.

 ∴ The number of possible outcomes =

Let W denote the event 'the marble is white', B denote the event 'the marble is blue' and R denote the event 'marble is red'

(i) The number of outcomes favourable to the event W =

So, P(W) =
Similarly, (ii) P(B) =
=
1
 and (iii) P(R) =

Note that P(W) + P(B) + P(R) = 1