Two integers are selected at random from the set {1, 2, …, 11}. Given that the sum of selected numbers is even, the conditional probability that both the numbers are even is

Explanation

Let A : Both the numbers selected are even
B: sum of selected numbers is even.
Given set is {1, 2, 3, ….,11}
Now, P(A|B)= `(n(AnnB))/(n(B))=(.^5C_2)/(.^6C_2+.^5C_2)=2/5`