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

Two numbers are selected at random from the set {1,2,3,....,13} . If the sum of the selected numbers is even, the probability that both the numbers are odd is

Two different numbers are selected at random from the set S={1, 2, 3, ……10}, then the probability that sum of selected numbers is divisible by 2 a/b, where a and b are co-prime then b is equal to ___.

Two different numbers are selected at random from the set S={1, 2, 3, ……10}, then the probability that sum of selected numbers is divisible by 2 a/b, where a and b are co-prime then b is equal to ___.

A number is selected at random from the set {1, 2, 3, …, 50}. The probability that it is a prime, is

Two integers are selected at random from integers 1 to 11. If the sum is even then the probability that both numbers are odd is

Two integers are selected at random from the integers 1 to 9. If their sum is even, then find the probability that both integers are odd.

Two integers are selected at random from the integers 1 to 9. If their sum is even, then find the probability that both integers are odd.

Three numbers are selected at random without replacement from the set of numbers {1,2,….n}. The conditional probability that the third number lies between the first two, if the first number is known to be smaller than the second is