14.Probability
easy

A bag contains $9$ discs of which $4$ are red, $3$ are blue and $2$ are yellow. The discs are similar in shape and size. A disc is drawn at random from the bag. Calculate the probability that it will be not blue,

A

$\frac{2}{3}$

B

$\frac{2}{3}$

C

$\frac{2}{3}$

D

$\frac{2}{3}$

Solution

There are $9$ discs in all so the total number of possible outcomes is $9 .$

Let the events $A, \,B, \,C$ be defined as

$A:$ 'the disc drawn is red'

$B:$ 'the disc drawn is yellow'

$C:$ 'the disc drawn is blue'.

Clearly the event 'not blue' is 'not $C'$ .

We know that $P $ (not  $C$ ) $=1- P ( C )$

Therefore $P$ (not  $C$ ) $=1-\frac{1}{3}=\frac{2}{3}$

Standard 11
Mathematics

Similar Questions

Start a Free Trial Now

Confusing about what to choose? Our team will schedule a demo shortly.