The question is:

Find the number of square tiles required to fill a given rectangle. If you use only part of a tile, then the rest is placed in the trash and can't be used.

Here is how I modeled it:

$\displaystyle n = \lceil{\frac{x}{t}}\rceil \times \lceil{\frac{y}{t}}\rceil$

Where n is the number of tiles required, x is the width of the rectangle, y is the length of the rectangle, and t is the size of the square tile.

Given some actual data:

The rectangle measures 25ft x 20ft.

The tile measures 2ft x 2ft.

$\displaystyle \lceil{\frac{25}{2}}\rceil \times \lceil{\frac{20}{2}}\rceil = 130$ tiles.

I'm running on like 2 hours of sleep, so I guess I'm just looking for verification that I'm doing this right. Thanks!