In how many ways can a team of $11$ players be formed out of $25$ players,if $6$ out of them are always to be included and $5$ are always to be excluded?

The number of ways $16$ identical cubes,of which $11$ are blue and the rest are red,can be placed in a row so that between any two red cubes there should be at least $2$ blue cubes,is

The solution set of ${ }^5 C_{x-1} > 2 \cdot { }^5 C_x$ is

The number of ways to select one or more books from $6$ books is:

If $^8C_r = ^8C_{r+2}$,then the value of $^rC_2$ is

$A$ committee of $7$ members is to be formed from $9$ boys and $4$ girls. In how many ways can this be done if the committee must consist of exactly $3$ girls?