Posted by Tasha on Sunday, May 23, 2010 at 1:01pm.
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?

math  Jen, Sunday, May 23, 2010 at 4:31pm
0% Nothing even is prime, because all even numbers can be divided by 2.

math (correction)  PsyDAG, Monday, May 24, 2010 at 11:39am
2 is the only prime even number. Since it is only 1 of the 11 possibilities, the probability = 1/11

math  D, Friday, September 10, 2010 at 2:23am
If you know that the number will be prime, than you only count the prime numbers; because there are 6 prime numbers in 111 and only one of those is even, the answer is 1/6.