If a team of 4 persons is to be selected out of 4 married couples to play mixed doubles- tennis game, then the number of ways of forming a team in which no married couple appears is

An eight digit number divisible by 9 is to be formed using digits from 0 to 9 without repeating the digits. The number of ways in which this can be done is

A string of letters is to be formed by using 4 letters from all the letters of the word "MATHEMATICS". The number of ways this can be done such that two letters are of same kind and the other two are of different kind is

The number of integers greater than 6000 that can be formed by using the digits $0,5,6,7,8$ and 9 without repetition is