The half-life of an isotope is the time for its mass to decay by k. For example, polonium- 210 has a half-life of 40. So, a sample of 100 g would decay to 50 g in 40 weeks. The
percent, P, of polonium remaining after t weeks is given by the formula P=100(0.5).
What percent, to the hundredth of a percent, of polonium remains after 30 weeks?