A number is selected from the set `{1, 2, 3,.., 20}`. The probability That the selected number is divisible by 3 or 4 is

A number is selected from the seet {1,2,3,. . . . . . 20} The probability that the selected number is divisible by 3 or 4 is ________

A number is selected from the set {2,3,…,30}. The probability that the selected number is a prime number is

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

Three numbers are selected simultaneously from the set (1,2,3,...,25). The probability that the product of the selected numbers is divisible by 4 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 ___.

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

If a number is selected from the first 30 natural numbers, then the probability that the number selected is divisible by 4 or 7, is

Three numbers are selected from the set {1,2,3,...,23,24}, without replacement.The probability that the selected numbers form an A.P.is equal to