If a number is chosen at random from the following list, what is the probability that it is not prime? 2, 3, 5, 7, 11, 13, 17, 19
We have the numbers:
2, 3, 5, 7, 11, 13, 17, 19
The prime number is an integer that is dividible by 1 and itself only.
We notice that all the abpve numbers are prime numbers.
Then the probability of getting a prime = 8/8 = 1
This is called a certain event.
The probability of getting a number that si NOT a prime = 0/8= 0
This is called an impossible event.
The list numbers given is: 2,3,5,7,11,13, 17 and 19.
The number of numbers are 8.
Each of these numbers are prime.
So the number of choices to make in a random choice = 8.
Since all the 8 numbers given in this list , 2,3,5,7,11,13 , 17 and 19, are primes, we are sure that any number chosen is a prime number.
Therefore number of favourable choices = 8.
The number possible choices is 8.
Therefore the probability that a chosen number from the list at random (or otherwise) is a prime = 8/8 = 1.