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Did you hear about the snake that liked maths?

I’m sure you did – it’s one of the oldest jokes in the book.*

Now get your fangs into today’s reptile-related riddle.

Snakes in a cage

Two snakes of equal width are in a cage. One is long and the other is short.

Design two escape passages, A and B, that lead from the bottom of the cage such that

The short snake can escape down A, but the long one can’t.

The long snake can escape down B, but the short one can’t.

The passages must have no moving parts, trapdoors or levers. Assume that the snakes have circular cross-sections, and the diameter is the same at all points along their bodies. The snakes can wiggle but they cant squeeze through passages that are narrower than they are wide.

I’ll be back at 5pm UK with solutions.

PLEASE NO SPOILERS.

* The offical answer is “adder” but I’m sure you can come up with something funnier in the comments below.

Source: Kvantik Magazine 2014.

I’ve been setting a puzzle here on alternate Mondays since 2015. I’m always on the look-out for great puzzles. If you would like to suggest one, email me.