At an election, a voter may vote for any number of candidates, not greater than the number to be elected. There are $10$ candidates and $4$ are of be selected, if a voter votes for at least one candidate, then the number of ways in which he can vote is
$5040$
$6210$
$385$
$1110$
Total number of $6-$digit numbers in which only and all the five digits $1,3,5,7$ and $9$ appear, is
The number of words not starting and ending with vowels formed, using all the letters of the word $'UNIVERSITY'$ such that all vowels are in alphabetical order, is
The number of ways of choosing $10$ objects out of $31$ objects of which $10$ are identical and the remaining $21$ are distinct, is
If $^{n} C _{9}=\,\,^{n} C _{8},$ find $^{n} C _{17}$