4 men,a tunnel 'n' a torch

[pisa]

Right, let's see who gets this. There r 4 men Tom,Dick,Harry and Cecil, and they have a torch that lasts 60 minutes. Now, you have to get them all to the other side of the tunnel before the torch runs out. You can only take 2 men at a time, then obviously 1 has to go back to pick the others up. Each man takes as follows to cross the tunnel:

Tom - 5 minutes

Dick - 10 minutes

Harry - 20 minutes

Cecil - 25 minutes

You have to calculate the slowest time, so for example, if you decide to take Tom and Harry first they will take 20 minutes, then Tom has to go back, so that's another 5 minutes making 30 minutes and so on. Remember, you have to get them all across within 60 minutes. 

[jenstar]

I don't get this. Why would you only be able to take 2 men through a tunnel at a time?

[Sputnik]

Tom & Dick make the first journey through the tunnel with the torch.  The time taken to cross is 10 mins (ie the slowest of time of the two).

Tom comes back with the torch - 5 mins.  He passes torch to Harry & Cecil, who both make the journey - 25 mins (again, slowest time of the two)

They pass the torch to Dick, who comes back through tunnel - 10 mins

Dick & Tom return through tunnel - 10mins

Total = 10 + 5 + 25 + 10 + 10 = 60mins!

[ursula62]

They'd have done it quicker if they gave each other piggy backs

[galltin]

Well done sputnik.

jenstar - why do all those blokes want dig all those holes? It's a mathematical puzzle that's all.

[pisa]

Well done Sputnik!How long did it take you...........to get thru the tunnel?