A bacteria has a doubling period of 10 days. If there are 2100 bacteria present now, how many will there be in 45 days?

First we must find the daily growth rate (Don't round up, keep all the decimal places).

The growth rate is:

There will be (_) bacteria.

2100 bacteria will become 4200 in 10 days, 4200 will become 8400 after 20 days, 8400 will become 16800 after 30 days, 16800 will become 33600. for the final 5 days you will add half of the double period. so half of 33600 is 16800. Now add those together. The answer is 50,400 bacteria after 45 days.