Suppose that a natural number from 1 through through 11 inclusive is selected at random. What is the probability that the number selected is even if you know that it is prime?
0% Nothing even is prime, because all even numbers can be divided by 2.
2 is the only prime even number. Since it is only 1 of the 11 possibilities, the probability = 1/11
If you know that the number will be prime, than you only count the prime numbers; because there are 6 prime numbers in 1-11 and only one of those is even, the answer is 1/6.
To find the probability of selecting an even number given that it is prime, we need to determine the number of even prime numbers and the total number of prime numbers.
First, let's identify the prime numbers between 1 and 11: 2, 3, 5, 7, 11. Among these, only the number 2 is an even number.
Therefore, there is only 1 even prime number. Since there are a total of 5 prime numbers between 1 and 11, the probability of selecting an even number given that it is prime is 1/5.
In summary, the probability of selecting an even number if you know that it is prime is 1/5.