A Certain Bacteria Doubles Every 20 Minutes. How Many Bacteria Will You End Up With If You Leave 10 Bacteria To Multiply For 4 Hours?

In 4 hours, the will be (4 hr)(60 min/hr)/(20 min/doubling) = 12 doublings.
10*2^12 = 10*4096 = 40,960
There will be 40,960 bacteria at the end of 4 hours.