# Thread: A very difficult question...

1. ## A very difficult question...

Note: There is no trick behind this. It is the simple movement of resources in the appropriate order. There are two known answers to this problem. This is based on a question Microsoft gives to all prospective employees. They expect you to answer this question in under 5 minutes.

"U2" has a concert that starts in 17 minutes and they must all cross a bridge to get there. All four men begin on the same side of the bridge. You must help them across to the other side.

It is night.
There is one flashlight.
A MAXIMUM of TWO people can cross at one time.
Any party who crosses, either 1 or 2 people, must have the flashlight with them.
The flashlight must be walked back and forth, it cannot be thrown, etc.

Each band member walks at a different speed.
A pair must walk together at the rate of the slower man's pace:
Bono: - 1 minute to cross
Edge: - 2 minutes to cross
Adam: - 5 minutes to cross
Larry: - 10 minutes to cross

For example: If Bono and Larry walk across first, 10 minutes have elapsed when they get to the other side of the bridge. If Larry then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission.

I have yet to figure this out. The only way I think I'm going to do this is to make a chart of all possible combinations.

2. Larry and Bono > = 10 minutes
Bono < = 11 minutes
Bono and Adam > = 16 minutes
Bono < = 17 minutes

Fuck.
I'm going to give up.
Took me 1:30 seconds to give this wrong answer.

4. Bono, flashlight + Larry, Bono goes back before Larry has crossed so 10 mins have pass, bono takes adam past and goes back before adam gets there 5 mins have passed, and finally he can take edge across = 17 mins.

Note: Bono keeps the flashlight all the time.

How long was that

5. Every time Bono goes back, you must add a minute because it takes him +1 to go across the bridge. So 10+5+2=17 +1+1+1=20. See what I mean?

I figure you have to think not using common sense. I figured:

Bono+Edge= 2 minutes
Bono< = 3 minutes

SEE I FUCKED UP. I DON'T GET IT.

6. No, he goes back WHILE the others are crossing

Another way
Bono + Larry < 10 mins
Then Bono crosses Right and Edge crosses left 12 mins
Finally Bono and Adam cross together 17 mins.

7. Originally Posted by Seemliss
I didn't have time for him anymore, that's why I lost.

8. larry and bono go together 10 mins
bono brings it back 1 mins
bono and edge go to gether 2 mins
bono brings back then go together with adam... 18 mins...
ah fuck this

9. I already sorted it, look:

Bono + Larry < 10 mins
Then Bono crosses Right and Edge crosses left 12 mins
Finally Bono and Adam cross together 17 mins.

10. wtf is that allowed.

11. Originally Posted by Epicfailur3
No, he goes back WHILE the others are crossing

Another way
Bono + Larry < 10 mins
Then Bono crosses Right and Edge crosses left 12 mins
Finally Bono and Adam cross together 17 mins.
NO, they HAVE to go together. They are pussies and need the flashlight, therefore your ways across cannot be made.

12. It doesn't say its not so fuck it it is. Also the flashlight shows the whole bridge no matter what side there on, Otherwise its impossible.

13. No, you must have two people go together, and it's not impossible. It says CLEARLY the flashlight must be walked back and forth, and it does not shine all the way across the bridge. There is no tricks, just simple and correct movements.

14. Bono and Edge go over, Bono comes back = 3 minutes
Larry and Adam go over, Edge comes back = 12 minutes
Bono and Edge come back = 2 minutes