A fiendishly clever brainteaser featuring a rickety old bridge and four desperate characters has taken the internet by storm, leaving thousands of Brits scratching their heads.
The premise seems simple enough: four people need to cross a bridge that's so dilapidated it can only support two people at a time. To make matters worse, it's pitch black, and they have just one torch between them.
The Rules That Make It Tricky
Here's what makes this puzzle so challenging:
- The bridge collapses if more than two people cross at once
- Someone must bring the torch back each time
- Each person crosses at different speeds
- You must get everyone across in 17 minutes or less
The four characters have very specific crossing times: one takes 1 minute, another 2 minutes, a third 5 minutes, and the slowest needs a full 10 minutes to cross safely.
Why This Puzzle Is So Addictive
What appears to be a straightforward task quickly becomes a complex logic problem that tests your strategic thinking. The temptation to send the fastest people back and forth seems logical at first, but this approach wastes precious minutes.
The real challenge lies in minimising the time spent on return journeys with the torch, while ensuring the slower members don't hold up the entire operation.
The Solution That Will Make You Kick Yourself
After you've spent considerable time rearranging the crossing order in your mind, the solution reveals an elegant simplicity. It involves pairing the slowest walkers together at strategic moments and using the fastest walker as the primary torch-runner.
The optimal solution sees everyone safely across in exactly 17 minutes - a result that surprises many who initially struggle to beat the 19-minute mark.
This type of logic puzzle has become incredibly popular on social media platforms, with friends challenging each other to beat the clock and solve it faster than their peers.
