SOLUTION: An ecoli bacteria divides every 20 minutes. After 120 minutes how many ecoli bacteria are there? Solve algebraically.

Question 68495: An ecoli bacteria divides every 20 minutes. After 120 minutes how many ecoli bacteria are there? Solve algebraically.
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
An ecoli bacteria divides every 20 minutes. After 120 minutes how many ecoli bacteria are there? Solve algebraically.
------------------------
A(t) = Ao (2)^(t/20)
Assuming you start with 1 bacteria you get:
A(120)=1(2)^(120/20)
=2^6=64
That is the number generated in the last 20 minutes.
---------------
The total number = 1+2+4+....+64
---------------
This is a geometric series with seven terms, a(1)=1, r=2:
S(7)= [r^(8)-1}/[r-1]= 127
--------------
Cheers,
Stan H.
-----------
RELATED QUESTIONS
EColi culture doubles every 40 minutes. If 30 EColi are present initially, what will the... (answered by ikleyn)

In a bacteria strain, the number of bacteria doubles every 20 minutes. There were 8... (answered by ikleyn)

A culture of bacteria doubles every 2 minutes. If there are 320 bacteria at the... (answered by Theo,ikleyn)

Bacteria grow by cell division. If each cell divides into 2 in every 2 minutes how many... (answered by nerdybill)

Bacteria grow by cell division. If each cell divides into 2 in every 2 minutes how many... (answered by stanbon)

2. Bacteria grow by cell division. If each cell divides into 2 in every 2 minutes how... (answered by nerdybill)

The bacteria E Coli are found in the human bladder. Suppose 3,000 bacteria are present... (answered by nerdybill)

There are initially 3 E-coli bacteria present in a hamburger. If the doubling time for... (answered by checkley71,bucky)

There are 800 bacteria originally in a culture. The doubling period is 20 mins. Write an... (answered by checkley79)