If you begin investing at age 45 instead of age 40, how much more do you need to invest per month to have $retirement ? Why this amount so much greater than the difference between 20 and 25?

The diameter of a bacteria colony that doubles every hour is represented by the graph below. what is the diameter of the bacteria after 8 hours? graph of a curve passing through the points zero comma 1, one comma two, two comma four, and three comma eight