Radioactive decay can be described by the following equation lnA=lnA0kt where A0 is the original amount of the substance, A is the amount of the substance remaining after time. t, and k is a constant that is characteristic of the substance. For the radioactive isotope phosphorus-32, k is 4.85102 days 1. If the original amount of phosphorus-32 in a sample is 73.6mg, how much phosphorus-32 remains after 11.5 days have passed? mg