Recent activity by nintendoit

In the given figure, $\text{PQRSTV}$ is a regular hexagon with each side of length $5\mathrm{~cm}.$ A circle is drawn with its centre at $ \mathrm{V}$ such that it passes...

In how many ways can cells in a $3 \times 3 $ grid be shaded, such that each row and each column have exactly one shaded cell? An example of one valid shading is shown. ...