P012 The rectangle

A rectangle is cut into smaller rectangles such that the cuts are parallel to the sides. Each sub-rectangle has the property that at least one pair of parallel sides has integral length.

Prove that the property holds for the original rectangle as well.

Several different proofs are known.

Hard Disk Sulking

Today’s disks are such prima donnas, they sulk when shouted at! Check out the video, and the technical explanation, at this blog entry by Gordon Haff.

Thanks to Avinash Patil for this link!