Suppose that a radioactive sample contains equal numbers of two radioactive nuclides A and B at t = 0. A has ahalf-life of 3.0 h, while B has a half-life of 12.0 h. Find the ratio of the decay rates or activities RA/RB at
(a) t = 0,
(b) t = 12.0 h, and
(c) t = 24.0 h.