## 23 Jan 2013

### Midweek Maths Puzzle: Crossing the Bridge

There are some mathematical questions where the first thing to do is to follow the rules and just ‘play the game’. After a bit of practice you start to figure out the patterns behind the rules. Then you can set about finding a solution.

This is a very old puzzle (old puzzles are old because they remain new, otherwise they’d just be forgotten puzzles) given a fresh lease of life with some computer animation. The rules are simple enough; to get all the people across the bridge in the minimum time. The full rules are on the Crossing the Bridge page.

I would like to add one small extension to the problem. Can you come up with your own similar puzzle but with different times for each person? Given that 5 people need to cross the bridge, can you come up with a simple formula to calculate the minimum possible time from each person’s individual time?

Answers and Extensions will be posted next Wednesday.

This is not a PMQ so feel free to discuss this puzzle in the comments section below.