Rotating Table

Screen Shot 2020-10-06 at 12.32.26 PM.png

The rotating table is spinning too fast for you to keep track of the coloured pads. But can you create a strategy to guarantee that you will win anyways?

A circular table has 4 pads, equally spaced around the perimeter, and each covered with an opaque screen. Beneath the screen, the pads are either red or blue. Every minute the table rotates for a few seconds at high speed.

During each interval between rotations, you are allowed to choose two pads, your choice. The screen over those two pads will open allowing you to see the colours of the pads. At that point you can reset the two colours to be whatever you want, red or blue. Then you close the two screens and the table is able to rotate again.

If at any point the pads all have the same colour, a bell rings and you have "won." The problem is, can you find a strategy which will guarantee a win in a finite number of moves?

Teacher Manual

Return To Activity Directory