Acommon inhabitant of human intestines is the bacterium escherichia coli. a cell of this bacterium in a nutrient-broth medium divides into two cells every 20 minutes. the initial population of a culture is 63 cells.

find the rate of growth after 8 hours. (round your answer to three decimal places.)

This is an example of exponential growth, determined an equation of the form P=Po*e^(kt), where Po is the initial value, P the value at time t. 

You can find the value of k, the relative growth rate, by substituting in the above equation. All the other questions are a matter of arithmetic.

Just plug-in the given values and you can now solve this problem yourself!

The answer is d. when it begins to fall back to the child's hand