Solve the Problem $\mathrm { A } = \mathrm { A } _ { \mathrm { o } } \mathrm { e } ^ { - 0.0099 \mathrm { t } }$

Multiple Choice

Solve the problem.
-The function $\mathrm { A } = \mathrm { A } _ { \mathrm { o } } \mathrm { e } ^ { - 0.0099 \mathrm { t } }$ models the amount in pounds of a particular radioactive material stored in a concrete vault, where t is the number of years since the material was put into the vault. If 900 pounds of the
Material are placed in the vault, how much time will need to pass for only 204 pounds to remain? Round to the
Nearest year.

A) 155 yr
B) 300 yr
C) 150 yr
D) 160 yr