Silicon Investor (SI) -- The First Internet Community

STOCKTALK

We've detected that you're using an ad content blocking browser plug-in or feature. Ads provide a critical source of revenue to the continued operation of Silicon Investor. We ask that you disable ad blocking while on Silicon Investor in the best interests of our community. If you are not using an ad blocker but are still receiving this message, make sure your browser's tracking protection is set to the 'standard' level.

Technology Stocks : Data Race (NASDAQ: RACE) NEWS! 2 voice/data/fax: ONE LINE! -- Ignore unavailable to you. Want to Upgrade?

To: R. Allan Choiniere who wrote (25942)	11/22/1997 1:05:00 AM
From: Eqmx	Read Replies (1) \| Respond to of 33268

Exactly on the 8th day!

To: R. Allan Choiniere who wrote (25942)	11/22/1997 1:13:00 AM
From: Marshall	Read Replies (2) \| Respond to of 33268

I see Serafino beat me to it. "doubles" and "half" are giveaways. I've been in too many Physics courses where the professor loved half-life problems.

To: R. Allan Choiniere who wrote (25942)	11/22/1997 1:17:00 AM
From: Marshall	Read Replies (1) \| Respond to of 33268

An Arab sheikh tells his two sons to race their camels to a distant city to see who will inherit his fortune. The one whose camel is slower will win. The brothers, after wandering aimlessly for days, ask a wise man for advice. After hearing the advice they jump on the camels and race as fast as they can to the city. What does the wise man say?

To: R. Allan Choiniere who wrote (25942)	11/22/1997 3:48:00 AM
From: Kashish King	Read Replies (1) \| Respond to of 33268

There's this pond about the size of two football fields with some duckweed on it. The duckweed doubles every day. Nine days later the entire pond is covered in slimy green duckweed. On what day was the pond half filled with duckweed? My intial reaction was Rastafarian until I realized that the answer was far simpler: If it doubles every day and if filled the pond in nine days it must have been half of that on the same day, by your stipulation. How easy can you get? Proof: Growth of the plant material is proportional to the amount present at any given time and it can be shown, rather easily, that this corresonds to the differential equation A( t ) = A * ( e ^ ( k * t ) ) where A is the amount, t is time, e is the magic number e, and k is some constant of the aforementioned proportionality. The implication was that there was half as much at some time in the past as there is now that the pond is full . We can plug those conditions into our equation and discover what that constant of proportionality is for duck weed based on the assumption that we have an amount A after 9 days: = > 2 * A = A * ( e ^ ( k * 9 ) ) => e ^ ( k * 9 ) = 2 => k * 9 = ln( 2 ) => k = ln( 2 ) / 9 => k = .077016 Now we have the all important constant of proportionality and, by extension, a general solution: A( t ) = A * ( e ^ ( .077016 * t ) ) Given a general solution, I can now give you a specific answer for when the amount was half of the current amount A: => 1/2 * A = A * ( e ^ ( .077016 * t ) ) => 1/ 2 = e ^ ( .077016 * t ) => ln( 1/2 ) = .077016 * t => t = - 9 The reason we get -9 and not 9 should be self-evident.