Can someone calculate this?
 

I was at a job interview today, and the guy asked me how many ping pong balls would fit into a 747.


I just kinda ball-parked, 800,000.

He just nodded, but asked another question, never gave me the answer. Now I am bugged, so does anyone know how this could be calculated, or if this is a standard job interview question?

Help!

I would be willing to ship some monies to anyone who can answer it.

Re: Can someone calculate this?
 

The idea is to see if you are any good at estimation. For example, estimate the length/diameter of the 747 and the diameter of the ping-pong ball, giving you their respective volumes, assume a packing fraction of w/e and you will get a rough answer.

Re: Can someone calculate this?
 

[ QUOTE ]
I was at a job interview today, and the guy asked me how many ping pong balls would fit into a 747.


I just kinda ball-parked, 800,000.

He just nodded, but asked another question, never gave me the answer. Now I am bugged, so does anyone know how this could be calculated, or if this is a standard job interview question?

Help!

I would be willing to ship some monies to anyone who can answer it.

[/ QUOTE ]

You wont get the job, learn from it and try again. These types of questions get asked in order to test your ability to reason through problems with limited information, estimate orders of magnitude, think logically, see how willing you are to ask questions to clarify problems when searching for a solution (and whether the questions you ask are intelligent), and to gauge your performance in an unfamiliar scenario. Just blurting out a ballpark estimate with no reasoning or dialog is probably the worst thing you could have done.

Re: Can someone calculate this?
 

[ QUOTE ]
[ QUOTE ]
I was at a job interview today, and the guy asked me how many ping pong balls would fit into a 747.


I just kinda ball-parked, 800,000.

He just nodded, but asked another question, never gave me the answer. Now I am bugged, so does anyone know how this could be calculated, or if this is a standard job interview question?

Help!

I would be willing to ship some monies to anyone who can answer it.

[/ QUOTE ]

You wont get the job, learn from it and try again. These types of questions get asked in order to test your ability to reason through problems with limited information, estimate orders of magnitude, think logically, see how willing you are to ask questions to clarify problems when searching for a solution (and whether the questions you ask are intelligent), and to gauge your performance in an unfamiliar scenario. Just blurting out a ballpark estimate with no reasoning or dialog is probably the worst thing you could have done.

[/ QUOTE ]

Depends, it could have been a job in advertising, and then the opposite applies. [img]/images/graemlins/grin.gif[/img]

Re: Can someone calculate this?
 

About 16,200,000?

Re: Can someone calculate this?
 

[ QUOTE ]
[ QUOTE ]
[ QUOTE ]
I was at a job interview today, and the guy asked me how many ping pong balls would fit into a 747.


I just kinda ball-parked, 800,000.

He just nodded, but asked another question, never gave me the answer. Now I am bugged, so does anyone know how this could be calculated, or if this is a standard job interview question?

Help!

I would be willing to ship some monies to anyone who can answer it.

[/ QUOTE ]

You wont get the job, learn from it and try again. These types of questions get asked in order to test your ability to reason through problems with limited information, estimate orders of magnitude, think logically, see how willing you are to ask questions to clarify problems when searching for a solution (and whether the questions you ask are intelligent), and to gauge your performance in an unfamiliar scenario. Just blurting out a ballpark estimate with no reasoning or dialog is probably the worst thing you could have done.

[/ QUOTE ]

Depends, it could have been a job in advertising, and then the opposite applies. [img]/images/graemlins/grin.gif[/img]

[/ QUOTE ]

Ha, touche.

Re: Can someone calculate this?
 

With no technical knowledge, you have to estimate.

An educated estimate? A ping-pong ball is 4cm in diameter. To make it easier, I'll just assume the balls stack neatly in 4cmx4cmx4cm cubes, 64cm^3 altogether. The cabin of the Boeing 747 is ~65m long, 6m wide, and I'll say 1.5m high (low, but I'm hoping to "shave off" the space I'm failing to take into account due to seats/curvature/etc and give myself an even number).

So 65m*6m*1.5m=585m^3 for the cabin, plus the listed 155.6m^3 for cargo, makes 740.6m^3, or 740,600,000cm^3. Divide by 64cm^3 is ~11.5 million balls. 800,000 is probably fine for a casual estimate. The real number is probably 5-10 million (I figure my estimate is high).

Re: Can someone calculate this?
 

I would have asked him how many tennis balls fit inside a 747, multiply that answer by 4 as a good estimate.

Re: Can someone calculate this?
 

[ QUOTE ]
About 16,200,000?

[/ QUOTE ]

I ballparked 15 million.

Re: Can someone calculate this?
 

fermi ballparked the first atom bomb energy within 5 minutes by ballparking. he was within 5% or something.

he said a lot is based on offsetting errors or something, I think you have to be expert in field to estimate the variables.