This morning I was lying in bed for a while before getting up, and an idea for a cute logical riddle came to me.
Four kids are standing in an amusement park holding a helium toy balloon. Each kid holds his own end of a thread, but there’s only one single toy balloon for the entire group. If any of the four kids let go of their own thread, the toy balloon will fly up to the sky and be lost, even if the remaining three kids keep holding to their respective threads.
How are the threads arranged? Post your answers in the comments!
Update: Many people solved the riddle in different ways that I didn’t think of in the comments. Congrats! Now your next task: Generalize the problem to N kids and M balloons, find the function that gives the number of threads needed for each combination, and then send a link to an interactive 3D plot of it :)