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The Puzzle

Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
The Puzzle

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.

Notes: 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.

Note: Microsoft expects you to answer this question in under 5 minutes!

Comments

  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    I can do it in 19. The crowd will have to wait. :p
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    19 as well.
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    OK OK.

    Bono + Edge cross. 2 mins

    Bono comes back with torch. +1 min = 3 mins

    Adam + Larry cross. +10 mins = 13 mins

    Edge comes back with torch. +2 mins = 15 mins

    Bono + Edge cross. +2mins = 17mins

    The alternative is deciding which of Bono & Edge comes back first.
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    well done.
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    I think it's designed to make you send the slowest guy first, but you have to work out the best way of getting the two slow ones across without having a slow return journey to do.

    Kept me amused for a while. :D
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    Shouldn't they be in a limo?

    Why are they only turning up that late?

    How big is the bridge?

    Why is Bono 10 times faster than larry?
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    Renzo wrote:
    Why is Bono 10 times faster than larry?


    Cos it's Bono :thumb:
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    Kentish wrote:
    OK OK.

    Bono + Edge cross. 2 mins

    Bono comes back with torch. +1 min = 3 mins

    Adam + Larry cross. +10 mins = 13 mins

    Edge comes back with torch. +2 mins = 15 mins

    Bono + Edge cross. +2mins = 17mins

    The alternative is deciding which of Bono & Edge comes back first.


    How long did it take you to work that out?
  • Former MemberFormer Member Posts: 1,876,324 The Mix Honorary Guru
    How long did it take you to work that out?
    A while ;)
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