Model Exponential Growth and Decay
Solve $\mathrm { A } = \mathrm { A } _ { 0 } \mathrm { e } ^ { - 0.0077 \mathrm { x } }$

Multiple Choice

Model Exponential Growth and Decay
Solve.
-The function $\mathrm { A } = \mathrm { A } _ { 0 } \mathrm { e } ^ { - 0.0077 \mathrm { x } }$ models the amount in pounds of a particular radioactive material stored in a concrete vault, where $x$ is the number of years since the material was put into the vault. If 300 pounds of the material are initially put into the vault, how many pounds will be left after 140 years?

A) 102 pounds
B) 192 pounds
C) 233 pounds
D) 96 pounds