Please proceed with caution - this riddle involves a rickety old bridge and serious brain wrinkling.
The premise behind the conundrum is simple:
- You're being chased by zombies
- There's four of you who need to cross a bridge before the zombies get to you
- Each of you walks at a different maximum speed
- Crossing the bridge in the dark requires huddling close to a latern
- The bridge can only hold two people at a time
- You need to get across and cut the bridge in 17 minutes

Watch the clip below and see if you can work it out - but remember to pause when you're asked to, because the solution is at the end....
https://www.youtube.com/watch?v=7yDmGnA8Hw0
Clip via TED-Ed