Math
posted by Erica .
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 Friday, a visitor from out of town told the police chief a new joke at 10:00a.m. How long did it take for everyone in Humorville to hear it?

after one hour, 3
after two hours, 9+3
after three hours, 27+9+3
so this is a geometric series,
3,9,27, ...3^t
The sum of a geometric series is
St=(13^t)/(13)=(13^t)/2
or
8500*(2)=13^t
17000=3^t
log17000=tlog3
t=8.86, but t is an integer, so t=9 hours.
check my work.
Respond to this Question
Similar Questions

math
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 … 
algebra
The population of humorville is 8500 people. In this town jokes travel fast. In one hour, each person who hears a joke tells three other people who have not herd it, and tells no one else. Last friday, a visitor from out of town told … 
math 157
at the first tri city meeting where 8 people are from twon A 7 people are from town B and 5 people are from town C. If the council consists of 5 people find the probability that 3 people are from town A and 2 people are from town B. … 
math 157
at the first tri city meeting where 8 people are from twon A 7 people are from town B and 5 people are from town C. If the council consists of 5 people find the probability that 3 people are from town A and 2 people are from town B. … 
Algebra
Question: Looking below is this answer correct? 
Math
The population of humorville is 8500 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 Friday, a visitor from out of town told … 
Language Art help
How does the great radio scare help you gain an understanding of past events? 
Precal
The number of people in a town of 10,000 who have heard a rumor started by a small group of people is given by the following function: N(t) = 10,000/(5 + 1245e.97t) 14. How many people were in the group that started the rumor? 
Math
In a community of 800 people the rate at which a rumor spreads is jointly proportional to the number of people who have heard the rumor and the number of people who have not heard it. Given that the rumor is spreading at the rate of … 
Algebra (answer check)
The population of a small town is decreasing at a rate of 6% per year. If the town's population is 12,500 in 2017, what will the population be in 6 years?