Strontium 90 is a radioactive isotope that decays according to the eqaution A t = A 0 e − 0.0244 t , where A 0 is the initial amount present and A t is the amount present after t years. If you begin with 400 grams of strontium 90,
(a) How much strontium 90 will be left after 10 years? Round your answer to the nearest tenth of a gram. grams
(b) When will 105 grams of strontium 90 be left? Round your answer to the nearest tenth of a year. years
HELP