$A$ committee of two persons is selected from two men and two women. What is the probability that the committee will have two men?

$A$ bag contains $10$ identical pens,of which $4$ are red and $6$ are blue. $3$ pens are taken out at random one after another. Find the probability that all $3$ are blue.

$A$ four-digit number is to be formed using the digits $1, 2, 3, 4, 5, 6, 7$ (no digit is repeated). What is the probability that the number formed is $> 4000$?

An old man forgets the last two digits of a telephone number. He dials these two digits randomly. What is the probability that he dials the correct number?

There are four machines and it is known that exactly two of them are faulty. They are tested,one by one,in a random order until both the faulty machines are identified. Then the probability that only two tests are needed is

$A$ five-digit number is formed using the digits $1, 2, 3, 4, 5$ without repetition. What is the probability that the number is divisible by $4$?