math

i don't know

Greatist possible sidelenght is 7cm and you need 39 766 tiles... ( given that you cannot cut the tiles, and you want tiles to all the four walls and the floor)

To find the sidelength you just have to find the greatis common divisor of the lenghts of the sides you need to tile(hint, you might have to change the lenghts to cm so you have integers to calculate the gcd from). When you know that it's just trivial to calculate the number of tiles.

x

Why can't you just cut the tiles that don't fit.
I have a tile cutter in my shed.
You could just have 5 tiles,
One for each side and one for the bottom.
the longest side is 11.34m so that is how long the tile would need to be.

of course, 22543, your interpetation is probably more what the teacher had in mind.