Two numbers a and b are selected successively without replacement in that order from the integers 1 to 10.The probability that `a/b` is an integer, is

Two numbers 'a' and 'b' are selected successively without replacement in that order from the integers 1 to 10. find the probability that a/b is an integer.

The integer is selected at random from 1 to 25. The probability that it is a prime number is

Three integers are chosen at random without replacement from the 1 st 20 integers.The probability that their product is odd is

Three integers are chosen at random without replacement from the first 20 integers. The probability that the product is odd is

Two numbers are selected at random from the integers 1 to 13. If the sum is even, find the probability that both numbers are odd

Two numbers a and b are chosen simultaneously from the set of integers 1, 2, 3, ….., 39, then the probability that the equation 7a-9b=0 is satisfied is