200μ Ci of iodine-131 is introduced into the body and decays with a half-life of 8 days.

(a) What is the initial activity in becquerels?
(b) What is the activity of the isotope 16 days after introduction, if the
biological half-life of the iodine is ignored?
(c) If the biological half-life of iodine-131 is 6 days, what is the effective half-life of the iodine and how much remains active in the body after 14 days?