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,
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 $C$ ) $=1-\frac{1}{3}=\frac{2}{3}$
The probability that an event will fail to happen is $0.05$. The probability that the event will take place on $4$ consecutive occasions is
Five horses are in a race. $Mr. \,A$ selects two of the horses at random and bets on them. The probability that $Mr.\, A$ selected the winning horse is
The probability of getting a number greater than $2$ in throwing a die is
Three houses are available in a locality. Three persons apply for the houses. Each applies for one house without consulting others. The probability that all the three apply for the same house is
Let $A$ be a set of all $4 -$digit natural numbers whose exactly one digit is $7 .$ Then the probability that a randomly chosen element of $A$ leaves remainder $2$ when divided by $5$ is ..... .