The number of bacteria, N(t), in a culture is given by the formula N(t)=2500*2^t/d, where t is the elapsed time in minutes and d is the doubling period. How can you manipulate that formula to determine the doubling period?

My second question is The half-life of sodium-24 is 14.9h. A medical facility buys a 50mg sample.
What would the exponential function be that models the amount of sodium-24 that will be present in the sample after t hours?
How much sodium-24 will remain after 24h?
How much time will elapse until only 12.5% of the original amount of sodium-24 remains?

Thank you.