In detail

Six glasses in a row

Six glasses in a row


We have six glasses in a row as seen in the first image. Three are full of water and three empty. Moving a single glass,


How can we make the full and empty glasses alternate as shown in the second image?

Solution

Take the second glass and pour the contents on the one in fifth position. Then put the glass back in place. Now we have alternate vessels and we have only touched one.

Pour the contents of the second glass over the fifth.