It takes 30 days to fill a laboratory dish with bacteria. If the size of the bacteria doubles each day, how long did it take for the bacteria to fill 1/64 of the dish?
Pick
A) 20
B) 22
C) 24
D) 26
E) 28
The bacteria doubles each day, so after 29 days, the dish was half full.   After 28 days, the dish was one quarter full.   After 27 days, the dish was one eighth full.   After 26 days, the dish was one sixteenth full.   After 25 days, the dish was 1/32 full.   After 24 days, the dish was 1/64 full.   The answer is 24.
<result>C</result>
It takes 30 days to fill a laboratory dish with bacteria. If the size of the bacteria doubles each day, how long did it take for the bacteria to fill 1/64 of the dish?