Gordian Knot

Rooting around in the dusty recesses of my office computer, I discovered a document containing the old U2 brainteaser, supposedly set by Micro$quash as a recruiting test, thus:

Allegedly, this is one of the questions for potential Microsoft employees. I must warn you, you can get really caught up in this problem. Reportedly, one guy solved it in two minutes. Another guy solved it by writing a C program - although it took him 37 minutes to develop it - the program solved it first go. A group of 50, at Motorola, couldn't figure it out at all. See how long it takes you!

OK here we go...

U2 (the band) have 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 may cross at one time. Any party who crosses, whether one or two people, must carry the flashlight with them. Thus the flashlight must be walked back and forth and cannot be thrown.

Each band member walks at a different speed. A pair must walk at 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 reach the other side. If Larry then returns with the flashlight, a total of 20 minutes have elapsed and you fail the mission.

You must get all 4 across in 17 minutes or less. There are two known solutions to the problem.

Note 1: There is no 'trick' behind this - it is the simple movement of resources in the appropriate order.
Note 2: Microsoft expects you to complete this in up to 5 minutes!

It strikes me that the sane solution would be to just cut the rope bridge, stranding the band and then use the concert receipts to fund some serious counselling for the audience. But that’s probably just me and my dislike of Mr. Paul (second coming) Hewson. You may know him as Bonio, and I for one would be happy to let a pooch gnaw at him if it gave said mutt a glossy coat.

If you’re interested, the solution is ( here )

Gordian Knot

Rooting around in the dusty recesses of my office computer, I discovered a document containing the old U2 brainteaser, supposedly set by Micro$quash as a recruiting test, thus:

Allegedly, this is one of the questions for potential Microsoft employees. I must warn you, you can get really caught up in this problem. Reportedly, one guy solved it in two minutes. Another guy solved it by writing a C program - although it took him 37 minutes to develop it - the program solved it first go. A group of 50, at Motorola, couldn't figure it out at all. See how long it takes you!

OK here we go...

U2 (the band) have 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 may cross at one time. Any party who crosses, whether one or two people, must carry the flashlight with them. Thus the flashlight must be walked back and forth and cannot be thrown.

Each band member walks at a different speed. A pair must walk at 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 reach the other side. If Larry then returns with the flashlight, a total of 20 minutes have elapsed and you fail the mission.

You must get all 4 across in 17 minutes or less. There are two known solutions to the problem.

Note 1: There is no 'trick' behind this - it is the simple movement of resources in the appropriate order.
Note 2: Microsoft expects you to complete this in up to 5 minutes!

It strikes me that the sane solution would be to just cut the rope bridge, stranding the band and then use the concert receipts to fund some serious counselling for the audience. But that’s probably just me and my dislike of Mr. Paul (second coming) Hewson. You may know him as Bonio, and I for one would be happy to let a pooch gnaw at him if it gave said mutt a glossy coat.

If you’re interested, the solution is ( here )

Cor, wotta pong.

I have been told that it's my turn to clean the kitty litter tonight. Oh joy; of such things are dreams made, and I didn't even want a cat (though I accept that looking after one temporarily is a slightly different matter).

Yesterday we even bought a 'scoop' to take care, as it were, of business.

I think ransacked ABBA lyrics cover it best:

Pooper Scooper, smells are gonna blind me
Makes my face turn blue
Like I always do
‘Cause somewhere in the grit there’s poo!

I offer a No-Prize to the person who completes the song best.

Cor, wotta pong.

I have been told that it's my turn to clean the kitty litter tonight. Oh joy; of such things are dreams made, and I didn't even want a cat (though I accept that looking after one temporarily is a slightly different matter).

Yesterday we even bought a 'scoop' to take care, as it were, of business.

I think ransacked ABBA lyrics cover it best:

Pooper Scooper, smells are gonna blind me
Makes my face turn blue
Like I always do
‘Cause somewhere in the grit there’s poo!

I offer a No-Prize to the person who completes the song best.