Homework Help: math

Posted by Brielle on Sunday, February 24, 2008 at 9:05pm.

the population of humorville is 8,500 people. in this town, jokes travel fast. in one hour, each person who hears a joke tells three other people who have not heard it, and tells no one else. last frieday, a visitor from out of town told the police chief a new joke at 10:00 a.m. how long did it take for everyone in humorville to hear the joke?

math - Reiny, Sunday, February 24, 2008 at 9:34pm
at 10:00 one person heard it
at 11:00 1 + 3 heard it
at 12:00 1 + 3 + 9 hear it
..
.

looks like a geometric series with
a=1
r = 3, and S_n = 8500

1(3^n - 1)/(3-1) = 8500
3^n - 1 = 17000
3^n = 17001
n = log 17001/lg3
n = 8.86 hours or appr 9 hours

so at 19:00 hrs, or in the US way of stating time, at 7:00 pm
- math - josh, Sunday, February 24, 2008 at 11:05pm
  poopie

Answer this Question

Related Questions

Math - The population of humorville is 8,500 people. In this town, jokes travel ...
algebra - The population of humorville is 8500 people. In this town jokes travel...
Algebra - Question: Looking below is this answer correct? If you follow the math...
URGENT MATH - The population of town A increases from 1,346 to 1,500. In the ...
Math - The population of town A increases from 1,346 to 1,500. In the same ...
MATHS - The population of town A increases from 1,346 to 1,500. In the same ...
Math 11u - A town has a population of 8400 in 1990. Fifteen years later, it'...
math - A town now has a population of 300,000 people and an annual growth rate ...
math - At the first tri-city meeting there are 8 people from town A, 7 people ...
Math - At the first tri-city meeting, there are 8 people from town A, 7 people ...

For Further Reading

First Name:
School Subject:
Answer: