Math Is Fun Forum

  Discussion about math, puzzles, games and fun.   Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ • π ƒ -¹ ² ³ °

You are not logged in.

#1 2007-04-05 20:31:14

justlookingforthemoment
Moderator
Registered: 2005-05-26
Posts: 2,161

Want to work for Bill Gates?

http://www.timesonline.co.uk/tol/life_a … 526400.ece

MICROSOFT, the world’s biggest software company, has developed its own unique — some would say eccentric — recruiting methods. It receives about 12,000 CVs each month. Without human intervention, each is scanned for key words and logged into a database. Promising résumés lead to a screening interview, usually by phone. Finally, those who pass muster get a “fly-back” — a trip to Microsoft’s headquarters in Redmond, Washington State, for a full-day marathon of famously difficult interviews.

“We look for original, creative thinkers,” says Microsoft’s website. “Our interview process is designed to find those people.”

At some point, a recruiter will lob in a so-called Microsoft question. It may be mathematical, with a “correct” answer, or open-ended. In either case the recruiter is at least as interested in the way you answer the question as in the answer itself.

“Get over your fear of trick questions,” says a company publication. “You will probably be asked one or two. They are not exactly fair, but they are usually asked to see how you handle a difficult situation.”

Some example 'Microsoft questions' ... discuss your answers!

1. How would you weigh a jet plane without using scales?

2. Why are manhole covers round rather than square?

3. Why is it that, when you turn on the hot water in a hotel, the hot water comes out instantly?

4. How do they make M&Ms?

5. How many times a day do a clock’s hands overlap?

6. You have eight billiard balls. One of them is “defective”, meaning that it weighs more than the others. How do you tell, using a balance, which ball is defective in two weighings?

7. You have two jars and 100 marbles. Fifty of the marbles are red, and 50 are blue. One of the jars will be chosen at random; then one marble will be withdrawn from that jar at random. How do you maximise the chance that a red marble will be chosen? (You must place all 100 marbles in the jars.) What is the chance of selecting a red marble when using your scheme?

8. You have a three-quart bucket, a five-quart bucket, and an infinite supply of water. How can you measure out exactly four quarts?

9. You have a bucket of jelly beans in three colours — red, green, and blue. With your eyes closed, you have to reach in the bucket and take out two jelly beans of the same color. How many jelly beans do you have to take to be certain of getting two the same colour?

10. Four people must cross a rickety footbridge at night. Many planks are missing, and the bridge can hold only two people at a time (any more than two, and the bridge collapses). The travellers must use a flashlight to guide their steps; otherwise they’re sure to step through a missing space and fall to their death. There is only one flashlight. The four people each travel at different speeds. Adam can cross the bridge in one minute; Larry in two minutes; Edge takes five minutes; and the slowest person, Bono, needs ten minutes. The bridge is going to collapse in exactly 17 minutes. How can all four people cross the bridge?

11. Why are beer cans tapered at the top and bottom?

12. How long would it take to move Mount Fuji?

Offline

#2 2007-04-05 20:59:21

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,710

Re: Want to work for Bill Gates?

2. Because square ones could fall through diagonally.


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

#3 2007-04-05 22:22:34

amateur
Member
Registered: 2007-02-11
Posts: 5

Re: Want to work for Bill Gates?

9. You have a bucket of jelly beans in three colours — red, green, and blue. With your eyes closed, you have to reach in the bucket and take out two jelly beans of the same color. How many jelly beans do you have to take to be certain of getting two the same colour?

Last edited by amateur (2007-04-05 22:49:25)


"In mathematics, you don't understand things. You just get used to them." - John von Neumann

Offline

#4 2007-04-05 22:35:08

amateur
Member
Registered: 2007-02-11
Posts: 5

Re: Want to work for Bill Gates?

10. Four people must cross a rickety footbridge at night. Many planks are missing, and the bridge can hold only two people at a time (any more than two, and the bridge collapses). The travellers must use a flashlight to guide their steps; otherwise they’re sure to step through a missing space and fall to their death. There is only one flashlight. The four people each travel at different speeds. Adam can cross the bridge in one minute; Larry in two minutes; Edge takes five minutes; and the slowest person, Bono, needs ten minutes. The bridge is going to collapse in exactly 17 minutes. How can all four people cross the bridge?

Last edited by amateur (2007-04-05 22:50:58)


"In mathematics, you don't understand things. You just get used to them." - John von Neumann

Offline

#5 2007-04-05 22:49:07

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,710

Re: Want to work for Bill Gates?

8. Did Bill Gates visit the Puzzle pages? Measuring 4 Liters


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

#6 2007-04-06 08:41:47

mathsyperson
Moderator
Registered: 2005-06-22
Posts: 4,900

Re: Want to work for Bill Gates?


Why did the vector cross the road?
It wanted to be normal.

Offline

#7 2007-04-06 10:14:11

amateur
Member
Registered: 2007-02-11
Posts: 5

Re: Want to work for Bill Gates?

mathsyperson wrote:

Your way seems to be the best! smile


"In mathematics, you don't understand things. You just get used to them." - John von Neumann

Offline

#8 2007-04-06 10:38:35

amateur
Member
Registered: 2007-02-11
Posts: 5

Re: Want to work for Bill Gates?

6. You have eight billiard balls. One of them is “defective”, meaning that it weighs more than the others. How do you tell, using a balance, which ball is defective in two weighings?


"In mathematics, you don't understand things. You just get used to them." - John von Neumann

Offline

#9 2007-04-09 04:38:03

scratch
Member
Registered: 2007-04-09
Posts: 1

Re: Want to work for Bill Gates?

[I saw this one quoted above, but couldn' see the solution--sorry if this is a repeat]

6.  Eight billiard balls:  Only weigh six of the balls, 3 on each side.  If one of the sides is heavier than the other, you weigh 2 of those balls.  If one of the 2 is heavier, you have your answer.  If not, then you know the 3rd ball is the heavier ball.  If the original 6 balls you weighed balance, then the heavier ball is one of the 2 you didn't weigh.  Weigh those 2 balls, and the heavier is the defective.  I hope that makes sense.

My favorite brain-teazer is something like this:  You find two light switches outside a room, and 3 lightbuls inside the room.  You need to determine which switch controls which bulb, but you can only flip each swich on and off one time, and you can only go inside the room once.

Offline

#10 2007-04-09 05:00:07

Zach
Member
Registered: 2005-03-23
Posts: 2,075

Re: Want to work for Bill Gates?

1. Using MAD. If MAD does not contain the relevant information, check the website.
2. Because a circle is more attractive to the eye.
3. Because they use a pre-emptive multitasking processor.
4. Fairies.
5. All clocks are digital on windows.
6. You don't. You release the product anyway and wait for customer feedback to determine which is faulty.
7. Place 25 Blue in the bottom of each jar and 25 red on the top of each jar. If the correct marble isn't picked, GNF, restart and try again.
8. By getting a four quart bucket. Doing so will require an update.
9. Two. If these are not the correct colours, then GPF and wait for an update and/or check if your copy of Microsoft JellyBeans is valid. If not, delete Jellybeans.
10. You cross the bridge yourself with the flashlight and wait for everyone else to get over. If they do not do it within the time limit, a GPF occurs and blue engulfs their eyes.
11. Just to make sure you really want to drink the beer. Are you sure? Positive? Absolutely sure? Definetly? You need an administrator for this. Do you want to grant yourself Admin Priv.? Yes? You sure? Positive?
12. Depends on the size of the file.


Boy let me tell you what:
I bet you didn't know it, but I'm a fiddle player too.
And if you'd care to take a dare, I'll make a bet with you.

Offline

#11 2007-04-09 05:24:41

Maelwys
Member
Registered: 2007-02-02
Posts: 161

Re: Want to work for Bill Gates?

1. How would you weigh a jet plane without using scales?

2. Why are manhole covers round rather than square?

3. Why is it that, when you turn on the hot water in a hotel, the hot water comes out instantly?

4. How do they make M&Ms?

5. How many times a day do a clock’s hands overlap?

6. You have eight billiard balls. One of them is “defective”, meaning that it weighs more than the others. How do you tell, using a balance, which ball is defective in two weighings?

7. You have two jars and 100 marbles. Fifty of the marbles are red, and 50 are blue. One of the jars will be chosen at random; then one marble will be withdrawn from that jar at random. How do you maximise the chance that a red marble will be chosen? (You must place all 100 marbles in the jars.) What is the chance of selecting a red marble when using your scheme?

8. You have a three-quart bucket, a five-quart bucket, and an infinite supply of water. How can you measure out exactly four quarts?

9. You have a bucket of jelly beans in three colours — red, green, and blue. With your eyes closed, you have to reach in the bucket and take out two jelly beans of the same color. How many jelly beans do you have to take to be certain of getting two the same colour?

10. Four people must cross a rickety footbridge at night. Many planks are missing, and the bridge can hold only two people at a time (any more than two, and the bridge collapses). The travellers must use a flashlight to guide their steps; otherwise they’re sure to step through a missing space and fall to their death. There is only one flashlight. The four people each travel at different speeds. Adam can cross the bridge in one minute; Larry in two minutes; Edge takes five minutes; and the slowest person, Bono, needs ten minutes. The bridge is going to collapse in exactly 17 minutes. How can all four people cross the bridge?

11. Why are beer cans tapered at the top and bottom?

12. How long would it take to move Mount Fuji?

There... now who wants to get me a job with M$?
And does calling it M$ instantly disqualify me from said job? ;-)

Offline

#12 2007-04-09 10:55:20

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,710

Re: Want to work for Bill Gates?

Nice solutions! Could 5 be simplified to "12 minus 1" ?

Maelwys wrote:

And does calling it M$ instantly disqualify me from said job? ;-)

I think using "M$" would earn you extra points, shows you understand the philosophy. up


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

#13 2008-10-12 03:31:27

All_Is_Number
Member
Registered: 2006-07-10
Posts: 258

Re: Want to work for Bill Gates?

1. How would you weigh a jet plane without using scales?

3. Why is it that, when you turn on the hot water in a hotel, the hot water comes out instantly?


You can shear a sheep many times but skin him only once.

Offline

#14 2008-10-12 09:06:54

MathsIsFun
Administrator
Registered: 2005-01-21
Posts: 7,710

Re: Want to work for Bill Gates?

Aha! So that's why the water stays hot!


"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Offline

Board footer

Powered by FluxBB