Can you work this out?!
Question: Four people need to be at a rendezvous in 17 minutes and they must all cross a bridge to get there.
All four men begin on the same side of the bridge. It is night and there is only one torch. The bridge is unsafe and a maximimum of 2 people can cross at any one time and they must have a torch with them to cross safely. The bridge is too long to throw the torch across, so it must be carried back and forth.
Each of the men walks at a different speed and if crossing together they must walk at the pace of the slowest man to use the torch effectively.
Adam would take 1 minute to cross
Ben would take 2 minutes
Caleb would take 5 minutes
Daniel would take 10 minutes
Can you work out the combination to get them across in 17 minutes?
Torch (flashlight)
Good Luck.
Answers: Four people need to be at a rendezvous in 17 minutes and they must all cross a bridge to get there.
All four men begin on the same side of the bridge. It is night and there is only one torch. The bridge is unsafe and a maximimum of 2 people can cross at any one time and they must have a torch with them to cross safely. The bridge is too long to throw the torch across, so it must be carried back and forth.
Each of the men walks at a different speed and if crossing together they must walk at the pace of the slowest man to use the torch effectively.
Adam would take 1 minute to cross
Ben would take 2 minutes
Caleb would take 5 minutes
Daniel would take 10 minutes
Can you work out the combination to get them across in 17 minutes?
Torch (flashlight)
Good Luck.
Adam and Ben will go first.. -2 (15 mins left)
Adam will go back w/the torch -1 (14 mins left)
Caleb and Daniel will go next -10 (4 mins left)
Ben will go back w/ the torch -2 (2 mins left)
Adam and Ben will now go to the others -2 (0 min)
there could be other way... but this is how I figured it out :)
Adam and Daniel cross first, 10 mins
Adam comes back.
Adam and Caleb next 5 minutes
Adam comes back
Adam and Ben next 2 minutes.
To be honest, I think this must be wrong because if Adam takes a minute to cross then the whole thing would actually take 19 minutes. but it woudn't come even close any other way
I thought as the man above. 17 minutes couldn't possibly take Adam's crossing back into account.
Adam takes everyone back and forth.
Well, the above actually fooled me too. And what we didn't realize(i guess) is that it doesn't have to be one of the last two people who went that returns. That is what makes it possible
Adam and Ben will go first: 2 min
Adam will go back w/the torch: 3 min
Caleb and Daniel will go next: 13 min
Ben will go back w/ the torch:15 min
Adam and Ben will now go to the others: 17min