You have a 7×7 board divided into 49 boxes. Mateo places a coin in a box.a) Prove that Mateo can place the coin so that it is impossible for Emi to completely cover the 48 remaining squares, without gaps or overlaps, using 15 3×1 rectangles and a cubit of three squares, like those in the figure.
https://cdn.artofproblemsolving.com/attachments/6/9/a467439094376cd95c6dfe3e2ad3e16fe9f124.png
b) Prove that no matter which square Mateo places the coin in, Emi will always be able to cover the 48 remaining squares using 14 3×1 rectangles and two cubits of three squares. geometrycombinatoricscombinatorial geometrytilesTiling