The bacteria in a 11 liter container double every 4 minutes. after 50 minutes the container is full. how long did it take to fill a quarter of the container?

To answer this item, we formulate an equation that would relate the time, rate, and the final time.

                             A(t) = (Ao)(2)^(t/4)

We solve for the value of Ao by substituting the known values,
                             11 = (Ao)(2)^(50/4)
                                   Ao = 1.89 x 10^-3

A quarter of 11 is 11/4. Using this value and the other known.
                             11/4 = (1.89 x 10^-3)(2)^(t/4)
The value of t from the equation is 42 minutes. 

The answer to your question is 1/9