The number of bacteria in a culture decreases according to a continuous exponential decay model. The initial population in a study is 400 bacteria, and there are 260 bacteria left after 6 minutes. A) Let t be the time (in minutes) since the beginning of the study, and let t be the number of bacteria at time t.

Write a formula relating y to t.
Use exact expressions to fill in the missing parts of the formula.
Do not use approximations.

B) How many bacteria are there 23 minutes after the beginning of the study?

Do not round any intermediate computations, and round your answer to the nearest whole number.