Please Login to access more options.
Problem (Which Dominoes Fell)
Suppose that Jon has set up an infinite number of dominoes, with the dominoes numbered $1,2,3, \ldots$. The dominoes are set up so that if the $k$th domino falls, then the $(k+1)$st domino will also fall. So if the 7th domino falls, then the 8th must fall as well. Jon knocks down the first domino. Which dominoes remain standing? Make sure you prove your result. The well ordering principle will come in handy.
The following pages link to this page.
Here are the old pages.