In how many ways can a committee consisting of one or more members be formed out of $12$ members of the Municipal Corporation?

The number of rectangles that can be obtained by joining four of $12$ vertices of a $12$-sided regular polygon is:

$20$ persons are invited for a party. In how many different ways can they and the host be seated at a circular table,if two particular persons are to be seated on either side of the host?

The number of ways that $8$ beads of different colours can be strung as a necklace is:

How many three-digit numbers can be formed from the digits $2, 3, 5, 6, 7,$ and $9$ which are divisible by $5$,given that no digit is repeated?

The number of permutations of $n$ things taken $r$ at a time,when $p$ things are always included,is