The Math Forum

Search All of the Math Forum:

Views expressed in these public forums are not endorsed by NCTM or The Math Forum.

Math Forum » Discussions » sci.math.* » sci.math

Notice: We are no longer accepting new posts, but the forums will continue to be readable.

Topic: Fly problem, alternative solution?
Replies: 6   Last Post: Oct 15, 2003 4:05 PM

Advanced Search

Back to Topic List Back to Topic List Jump to Tree View Jump to Tree View   Messages: [ Previous | Next ]
de Valmont

Posts: 23
Registered: 12/12/04
Re: Fly problem, alternative solution?
Posted: Feb 8, 1997 2:29 PM
  Click to see the message monospaced in plain text Plain Text   Click to reply to this topic Reply

> If you notice the whole thing lasts 2 hours, you see at once the
> answer is 150 miles.
> But you might instead work out that the first leg of the fly's
> trip lasts 1.6 hours and is 120 miles long; the second leg is 1/5 as
> long, 24 miles; the third, likewise, is 4.8 miles; and so on. You sum
> the infinite series (a geometric one)... and get 150 miles, the hard way.

Yes, it is rather simple:

s1*SUM(C^n,n=1,oo) where C = V1/V2 (If you have one train as a refernece point)

> The story goes, someone gave this to von Neumann and the latter gave
> the answer in a few seconds.
> -- "Ah, of course you saw the quick method... You know, some people
> try to sum the infinite series..."
> -- "What do you mean?... I _did_ sum the infinite series..."

I've heard that one before.


Point your RSS reader here for a feed of the latest messages in this topic.

[Privacy Policy] [Terms of Use]

© The Math Forum at NCTM 1994-2018. All Rights Reserved.