19 Nov 05
4 musicians are on one side of a bridge at night and need to
reach the other side in the next 16 minutes.
They only have 1 flashlight and so must travel in pairs accross
the bridge, with one person returning with the flashlight for the next pair.
Going across, the pairs must walk at the speed of the slowest person.
The 4 musicians take 1,2,5 & 9 minutes to cross the bridge
respectively.
How do they manage to do it?
This is not a trick question but one of resource management.
n.b there are 2 answers.
19 Nov 05
Originally posted by Thequ1ckSolution I:
4 musicians are on one side of a bridge at night and need to
reach the other side in the next 16 minutes.
They only have 1 flashlight and so must travel in pairs accross
the bridge, with one person returning with the flashlight for the next pair.
Going across, the pairs must walk at the speed of the slowest person.
The 4 musicians take 1,2,5 & 9 mi ...[text shortened]... it?
This is not a trick question but one of resource management.
n.b there are 2 answers.
- 2 and 1 go over (2 min)
- 1 comes back (1 min)
- 9 and 5 go over (9 min)
- 2 comes back (2 min)
- 2 and 1 go over (2 min)
Total time = 16 minutes
Solution II:
- 2 and 1 go over (2 min)
- 2 comes back (2 min)
- 9 and 5 go over (9 min)
- 1 comes back (1 min)
- 2 and 1 go over (2 min)
Total time = 16 minutes
The main idea is to never waste time sending 9 or 5 back, and also to 'eliminate' the 5-minute guy from the addition.
19 Nov 05
Originally posted by BigDoggProblemVery good. Most people take many hours to solve that one.
Solution I:
- 2 and 1 go over (2 min)
- 1 comes back (1 min)
- 9 and 5 go over (9 min)
- 2 comes back (2 min)
- 2 and 1 go over (2 min)
Total time = 16 minutes
Solution II:
- 2 and 1 go over (2 min)
- 2 comes back (2 min)
- 9 and 5 go over (9 min)
- 1 comes back (1 min)
- 2 and 1 go over (2 min)
Total time = 16 minutes
The main idea ...[text shortened]... er waste time sending 9 or 5 back, and also to 'eliminate' the 5-minute guy from the addition.
The catch is understanding that the torch can be passed.
27 Nov 05
Originally posted by Thequ1ckI haven't read any answers yet.
4 musicians are on one side of a bridge at night and need to
reach the other side in the next 16 minutes.
They only have 1 flashlight and so must travel in pairs accross
the bridge, with one person returning with the flashlight for the next pair.
Going across, the pairs must walk at the speed of the slowest person.
The 4 musicians take 1,2,5 & 9 mi ...[text shortened]... it?
This is not a trick question but one of resource management.
n.b there are 2 answers.
Heres mine,
2 & 1 = 2
2 = 2
5 & 9 = 9
1 = 1
2 & 1 = 2
Total = 16
Took a little while to figure out how to get 5 & 9 across together.
28 Nov 05
1 edit
Originally posted by BigDoggProblemBecause i didn't scroll down and hence didn't see your post till afterwards. You see there is this thing called willpower, it's quite useful.
Eh, just admit you stole the answer from me. How could you ignore it when it's the 2nd post in the thread?
30 Nov 05
Originally posted by BigDoggProblemIt is not so much the size of the monitor as its resolution setting. Plus, RHP has a rather wide top margin before the actual contents of the posts start. I see less than one half of the second post, with resolution set to 1024 x 768 (I know, I'm an old blind bat and have to have big text 🙂
You must have a tiny monitor if you have to scroll down just to see the 2nd post in a thread...