Real-World Word Problems OSU Marion Math 148

Math 148 Au2006
OSU Marion
Dr. Maharry

Get Extra Credit in Math 148 Au06 from Dr. Maharry

2 points (up to a max of 20 points for the class) for each nice example of a Real-Life word problem that you have found. A web lnk is nice, but not necessary. If you can tie it into something we're working on in class, that is even better.
2 points (up to a maximum of 10 points for the class) for each nicely written solution to someone else's problem you found on this page. Hand it in to me or email it to me at maharry@math.ohio-state.edu

Problem 9

Vampires a Mathematical Impossibility, Scientist Says Sara Goudarzi
LiveScience Staff Writer
LiveScience.com
Wed Oct 25, 5:15 PM ET

A researcher has come up with some simple math that sucks the life out of the vampire myth, proving that these highly popular creatures can't exist.

University of Central Florida physics professor Costas Efthimiou's work debunks pseudoscientific ideas, such as vampires and zombies, in an attempt to enhance public literacy. Not only does the public believe in such topics, but the percentages are at dangerously high level, Efthimiou told LiveScience.

Legend has it that vampires feed on human blood and once bitten a person turns into a vampire and starts feasting on the blood of others.

Efthimiou's debunking logic: On Jan 1, 1600, the human population was 536,870,911. If the first vampire came into existence that day and bit one person a month, there would have been two vampires by Feb. 1, 1600. A month later there would have been four, and so on. In just two-and-a-half years the original human population would all have become vampires with nobody left to feed on.

If mortality rates were taken into consideration, the population would disappear much faster. Even an unrealistically high reproduction rate couldn't counteract this effect.

"In the long run, humans cannot survive under these conditions, even if our population were doubling each month," Efthimiou said. "And doubling is clearly way beyond the human capacity of reproduction."

So whatever you think you see prowling around on Oct. 31, it most certainly won't turn you into a vampire.

Here's the question: I'm not sure I believe this person's logic about vampires. He assumes that Vampires bite one person per month. Where did he get that information? How did he get the fact that it would take 2 1/2 years for every human to become a vampire?

Maybe vampires only need to feed much less frequently. Suppose on Jan1, 1600, there was exactly 1 vampire in existance. How often would each vampire bite a person (and thus make another vampire) in order for there to be one million vampires roaming the earth this halloween.

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