Calculus Question

Question

A sample of a radioactive substance decayed to 93.5% of its original amount after a year. (Round your answers to two decimal places.)

(a) What is the half-life of the substance?

_____ yr

(b) How long would it take the sample to decay to 70% of its original amount?

 _________yr

Answer 1

(a) 0.935 = e^k

(b) 0.70 = e^kt Use the value of k from (a)