Stretch your brain: can you solve this riddle?
The zombies are upon you and you have to get the lab team across the bridge in 17 minutes. Can you solve the riddle?
Alex Gendler bridge riddle

TED-Ed editor and fun guy Alex Gendler has come up with this fun take on the classic river-crossing riddle, with catchy animation by Artrake Studio, and it shows how much fun maths can be.

If your teen is set on a career in programming, studying and solving riddles and puzzles could help to develop the right skills. Some big-name software corporations are even said to include some of these riddles in their application tests.

River-crossing puzzles are older than a thousand years and were devised to help children develop logic and reasoning skills. The premise goes something like this: you have x amount of people or items on the one side which need to get to the other side – but there are restrictions in the amount of objects that can cross simultaneously, or combination of objects that can safely huddle together on the riverbed.  

Classic examples are the fox, chicken and bag of feed puzzle, the missionaries and cannibals or married spouses riddle, and the bridge and torch puzzle. 

In Gendler's bridge riddle, you have a scientist (you), a lab assistant, a professor and a janitor. Seventeen minutes behind you is a horde of zombies and before you lies a gaping gorge. The four of you need to cross the bridge, which can only hold two people at a time. It's pitch dark and everyone crossing needs the light of the small lantern you managed to grab. You can dash across in 1 minute, the lab assistant in 2 minutes, the janitor in 5 minutes, and the weak professor in 10 minutes. You only have 17 minutes. 

Watch the riddle here – the solution is at 2 minutes:

Can you get everyone across in time?

If you know of other great riddles and games kids can play to develop their logical thinking and reasoning skills, let us know at

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