Question

What is the probability of a number selected from the numbers 1,2,3....,20 such that
it is a prime number?
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Answer 1

P(prime number)=9/20

Prime number are those which can divisible by 1 and itself

Answer 2

Given:

We have given the number from 1 to 20.

To Find:

We have to find the probability of getting a prime number?

Step-by-step explanation:

• The probability of any event is known as the possibility of occurring that particular event.
• We have 20 numbers from 1 to 20.
• Thus the sample space of number is written below

        $SS=1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,1,718,19,20$

• In the above sample space of number prime numbers are 2,3,5,7,11,13,17,19

• Thus there are total of 8 prime numbers in counting from 1 to 20.
• We know the formula of getting the probability of any event is given by the favorable outcome divided by the total number of outcomes.

      $P(E)=\frac{\textrm{favourable outcome}}{\textrm{total number of outcome}}$

• We have a total number of outcomes is 20.
• A number of favorable outcomes is 8. put the values in the above equation.

$P( prime)=\frac{8}{20} =\frac{2}{5}$

Hence, the probability of getting prime number is $\frac{2}{5}$.