Irradiation, Neutron Beam, Activity, Nuclear Reaction Help Please!?

Your question is how to start this. So what you should do first is, by following the steps, plot a graph of the number of I-128 nuclei present as a function of time. So, make a visual graph. Your equation should work for B. C will require both data from A and B, It will come to you as you go. and D should result from C.