SOLUTION: A bacteria population starts at 2032 and decrease by 15% everyday. Write a function representing the number of bacteria present each day. After how many days will there be

Algebra.Com
Question 198168: A bacteria population starts at 2032 and decrease by 15% everyday.
Write a function representing the number of bacteria present each day.
After how many days will there be fewer than 321 bacteria?
I need some help on this problem please.
Thank you in advance.

Found 2 solutions by ankor@dixie-net.com, arallie:
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
A bacteria population starts at 2032 and decrease by 15% everyday.
Write a function representing the number of bacteria present each day.
f(t) = 2032(1-.15)^t
f(t) = 2032*.85^t
:
After how many days will there be fewer than 321 bacteria?
2032*.85^t = 321
.85^t =
.85t = .1578
t*log(.85) = log(.1578)
-.07058t = -.80189
t
t = 11.36 days
We can say after 12 days there will be less than 321
:
Check solution on calc: enter 2032*.85^12 = 289 left which is less than 321
in 11 days: 2032*.85^11 = 340, more than 321

Answer by arallie(162)   (Show Source): You can put this solution on YOUR website!






RELATED QUESTIONS

Please help. Show step by step. Thanks A bacteria culture starts with 500 bacteria... (answered by KMST)
NEED HELP ASAP PLEASE!! A bacteria culture starts with 2000 bacteria and the population... (answered by dabanfield)
A bacteria culture starts with 560 bacteria and grows at a rate proportional to its size. (answered by Theo)
Please help me with this every answer I have tried is wrong. A bacteria culture starts (answered by robertb)
A bacteria culture starts with 600 bacteria and after 3 hours there are 2400. Find the... (answered by ewatrrr)
The generation time G for a particular bacteria is the time it takes for the population... (answered by josgarithmetic)
The generation time G for a particular bacteria is the time it takes for the population... (answered by ankor@dixie-net.com)
At 2pm the number of bacteria in a colony was 100, by 4pm it was 4000. Write an... (answered by ankor@dixie-net.com)
four bacteria are placed in a jar, and the number of bacteria doubles everyday. the jar... (answered by jorel1380)