Question

Find the probability that a number selected at random from the numbers 1 to 25 is not a prime number when each of the given number is equally likely to be selected.

Answer 1

Hey! :)

Probability = 9/25
As No . of Prime Numbers Between 1-25 = 9
And Total no.Of Number Cards = 25

Hope this helps! :)

Answer 2

Total number ( 1,2,3,4,...., 25) = 25.
Out of 25 numbers prime numbers = 2,3,5,7,11,13,17,19,23 = 9 Prime numbers
So, remaining not a prime number are 25 - 9 = 16
Total number of possible outcomes = 25
and number of favourable outcomes = 16


`P = ( Number \: of \: favourable \: outcomes )/( Total \: number \: of \: possible \: outcomes)`


`P(not \: a \: prime) = (16)/(25)`