Number of ways in which the number 831600 can be split into two factors which are relatively prime is

If 4 letters are selected at random from the letters of the word PROBABILITY, then the probability of getting a combination of letters in which atleast one letter is repeated is

The number of ways of arranging all the letters of the word 'COMBINATIONS' around a circle so that no two vowels together is

If all the numbers which are greater than 6000 and less than 10000 are formed with the digits, $3,5,6,7,8$ without repetition of the digits, then the difference between the number of odd numbers and the number of even number among them is