You have an empty container, and an infinite number of marbles, each numbered with an integer from 1 to infinity.

At the start of the minute, you put marbles 1 - 10 into the container, then remove one of the marbles and throw it away. You do this again after 30 seconds, then again in 15 seconds, and again in 7.5 seconds. You continuosly repeat this process, each time after half as long an interval as the time before, until the minute is over.

Since this means that you repeated the process an infinite number of times, you have "processed" all your marbles.

How many marbles are in the container at the end of the minute if for every repetition (numbered N)

A. You remove the marble numbered (10 * N)

B. You remove the marble numbered (N)

(In reply to Respectfully, I disagree with someone. Maybe. by Sam)

Sam,
Thanks, as I said from square one I am not a throretical math guy. This appears to mean I lack some vocabualary.
The problem says taht you continue to process marbles until the minute is over and then asks haow many marbles you had at the end of the minute.
I took this to be asking how many marbles you had after you stopped processing. As you said, if you stop, you have a finite set. That states simply was I was awkwardly trying to say.

Since it seems to be agreed that once you stop (if you could stop) then there is a finite number (however large) of marbles that have been processed.

Sorry for having wasted eveyones time.

IT does raise the interesting quetion of what are you doing in the 62nd second? The minute is over, according to math theory you've processed "all" of your infinite set of marbles before the 61st second. But you never stopped processing them.

I'm sure that this has been explored before so if someone could post me the stock solution I'll be fine.

special to SK. Don't worry, I do not take it personally. I know that you and others are not being nasty. I'm really not THAT thin skinned (hence my name)

Posted by FatBoy on 2003-09-10 07:54:39