This is a geometric sequence, where the function is 2n, n being the number of bacteria.
Divide 40,000 by 2. 5th hour.
20,000 is the answer, divide 20,000 by 2. 4th hour.
10,000 is the answer, divide 10,000 by 2. 3rd hour.
5,000 is the answer. Divide 5000 by 2 2nd hour.
2,500 is the answer. Divide by 2 to find the initial amount. 1st hour.
The initial amount is 1,250 bacteria.
Hope this helped! :D
