Solve the Problem $$\mathrm { A } = \mathrm { Ie }^{ { kt }}$$

Multiple Choice

Solve the problem.
-In the formula A $$\mathrm { A } = \mathrm { Ie }^{ { kt }}$$ A is the amount of radioactive material remaining from an initial amount I at a given time t and k is a negative constant determined by the nature of the material. A certain radioactive isotope has a
Half-life of approximately 1450 years. How many years would be required for a given amount of this isotope to
Decay to 60% of that amount?

A) 1069 yr
B) 580 yr
C) 1009 yr
D) 1917 yr