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        riddles >> easy >> The Beatles
        
(Message started by: Micah on Dec 10^th, 2002, 3:39pm)

Title: The Beatles
Post by Micah on Dec 10^th, 2002, 3:39pm

The Beatles have a show they need to play, but they have to cross a bridge to get to the stage. The bridge can only hold a maximum of two band members at a time and is very dark, so a flashlight is required to cross the bridge. The band members are able to cross the bridge at different speeds, but the group of two crossing at any given time can only go as fast as it's slowest member. Assuming these times of crossing the bridge: John= 1min. Paul= 2min. George= 5min.
Ringo= 10min....Can you get the band to the stage in 17 min.?

Note: There is only 1 flashlight, so remember to account for the time it takes to take the flashlight back to other band memebers.

Title: Re: The Beatles
Post by Micah on Dec 10^th, 2002, 3:48pm

another version of the riddle to clarify any loopholes in original wording:

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 in under or at 17 minutes. 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 the get to the other side of the bridge. Larry then returns with the flashlight, a total of 20 minutes have passed and you have failed the mission. There is no trick behind this. It is 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!

Good Luck!

Title: Re: The Beatles
Post by Garzahd on Dec 10^th, 2002, 5:51pm

Microsoft does NOT give this question to ALL prospective employees, but has given it to at least one in the past. :-)

Micah, did you take this from 15-251 at CMU?

Title: Re: The Beatles
Post by SgtAcid on Dec 10^th, 2002, 8:32pm

Answer for the U2 riddle:

Bono & Edge go first = 2 mins
Bono comes back = 3 mins
Adam & Larry go next = 13 mins
Edge comes back= 15 mins
Bono & Edge go across = 17 mins

And the part about time, lets just say I didn't get the job at Microsoft.