Henk Reuling posted a deceptively simple-looking geometric problem on Twitter.
“I found this old one cleaning up my ‘downloads’ [source unknown] I haven’t been able to solve it, so help!
According to the given information in the figure, what is the length of the missing interval on the diagonal of the square?”
See the Missing Interval Puzzle.
This is a nice variation on the typical clock problem posed by Cary Mallon and retweeted by Henk Reuling:
“This clock has fallen on the floor, and unfortunately, there is no indication which way ‘up’ the clock should hang. However, both hands are pointing precisely at the [adjacent] minute marks. You can now work out what the time is.”
See the Fallen Clock Puzzle.