Permutations an...

The number of ways of dividing 15 men and 15 women into 15 couples each consisting of a man and a woman is _______

The number of times the digits 3 will be written when listing the integers from 1 to 1000 is _______

The number of ways of distributing 52 cards among four players so that three players have 17 cards each and the fourth player has just one card is _______

In a circus there are 10 cages for accomodating 10 animals out of these 4 cages are so small that five out of ten animals can not enter into them.In how many ways will it be possible to accomodate 10 animals in these 10 cages?

The number of 4 digits number which do not contain 4 different digit is _______

A man has 7 relative, 4 of them ladies and 3 gentleman. his wife also have 7 relatives. 3 of them ladies and 4 gentlemen, They invite for a dinner partly 3 laddies and 3 gentlemen so that there are 3 of the men's relative and 3 of the wife's relative. The number of ways of invitation is _______

Find the number of chords that can be drawn through 16 points on a circle.

The number of arrangements of two letter of the words "BANANA" in which two of N's do not apper adjacently is _______

The number of the factors of 20! is _______