If $5$ parallel lines are intersected by $4$ parallel lines,then what is the number of parallelograms formed?

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

There are $11$ points in a plane,of which $5$ points are collinear. The total number of distinct quadrilaterals that can be formed with vertices at these points is:

The crew of an $8$-oar boat is to be chosen from $12$ men,of whom $3$ can row on the stroke side only. The number of ways in which the crew can be arranged is

$A$ set of $10$ parallel lines is intersected by another set of $m$ parallel lines. If the total number of parallelograms formed by these two sets of lines is $675$,then $m$ is equal to:

Out of $30$ points in a plane,$8$ of them are collinear. The number of straight lines that can be formed by joining these points is: