Answer:
Approximately 0.0121 will be left after 15 days.
Explanation:
We can write an exponential function to model the situation. The standard exponential function is given by:

Let x represent the amount of days. Since the initial amount is 3,820 pounds, a = 3820. It decays at a rate of 57% per day. So, after one day, it will only have 100% - 57% = 43% or 0.43 of its previous amount. So, b = 0.43.
Hence, our function is:

After 15 days, x = 15. Substitute and evaluate:
