A Coin Puzzle

by Sheridan Cole 734 views0

Puzzles are not magic, but the effect they have on the ego is! This trick is a beautiful piece of puzzle construction, because it relies on the human eye to mess things up, which it usually dies anyway. Once you have taken the time to memorize the movements required to solve the puzzle, you will have a lot of fun watching your friends try to beat it. They will try to beat it, and very confidently, too, because you can show them the puzzle once for free, and they will still fail to get it right 99 percent of the time!

A Few Coins, a Few Beers, a Few Freakouts

This puzzle needs two types of coins, easily distinguishable from each other. Different colors are a good idea. Arrange your two types of coins like this: A – B – A – B – A. Here are the rules for the puzzle:  You are trying to rearrange the coins into a line that reads like this: A – A – B – B – B. You can only move the coins in pairs, and each pair must have one of each type, as AB or BA. You can only move a pair if they are touching at the start of the move, but if they are separated by a gap as you shift the coins around, the pair cannot be moved. For example: imagine that you start out by moving the second and third coins to the far end of the row, so that the you create a line that reads like this: A – gap – gap – B – A – B – A. The rules state that you cannot combine the first A coin with any other in a move, and the B coin that is placed after the gaps cannot be combined with the first A, although the third coin is okay. The last rule requires a two-minute time limit. Some would consider this sadistic, but you will be reasonable – tell your friends and victims that you’ll allow them to watch you solve the puzzle once!  Go ahead and do it. The shifting of the coins and the human eye conflict and argue. It will take an amazingly sharp eye to see the pattern after just one look.

You can now ignore the types of coins if you strictly follow the patterns of movements that are listed next!

Imagine the coins labeled with numbers. From the starting position, they will read like this:
1 – 2 – 3 – 4 – 5  / the First Move takes coins 4 and 5 from the right to the left end. This leaves the coins in this position:
4 – 5 – 1 – 2 – 3 / now the Second Move takes coins 2 and 3 from their places at the far left to the other end, copying your first move. This move creates this pattern:
2 – 3 – 4 – 5 – 1 / now the Third Move starts in a different place, taking coins 4 and 5 to the far left. This will leave your first gap in the line, and you will need to be careful not to knock any coins too far off the line or rampant confusion will ruin the trick. This move creates this pattern:
4 – 5 – 2 – 3 – space – space – 1 / now the Fourth Move switches the gap to the other end of the line, taking coins 5 and 2 to the gap. This creates the next pattern:
4 – space – space – 3 – 5 – 2 – 1 / the Fifth Move gives you the solution to the puzzle, as you move the last pair at the right into the gap at left, and it looks like this:
4 – 2 – 1 – 3 – 5!

Congratulate yourself on your skills as your friends storm away, frustrated by their inability to figure out something that took you three hours to memorize. For a good visual of this trick, check this site: