Write the word or phrase that best completes each statement or answers the question.
-A sample of 200 grams of radioactive substance decays according to the function $A ( t ) = 200 \mathrm { e } ^ { - .048 t }$, where $t$ is the time in years. How much of the substance will be left in the sample after 20 years? Round your answer to the nearest whole gram.
A) $0 \mathrm {~g}$
B) $77 \mathrm {~g}$
C) $423 \mathrm {~g}$
D) $1 \mathrm {~g}$

Question

Quizplus · Accepted Answer

To find the amount of substance left after 20 years, substitute $t = 20$ into the given function: $A(20) = 200e^{-0.048 \times 20}$. Calculating this gives approximately $77 \mathrm {~g}$, rounding to the nearest whole gram.

Write the Word or Phrase That Best Completes Each Statement A(t)=200e−.048tA ( t ) = 200 \mathrm { e } ^ { - .048 t }A(t)=200e−.048t

Write the Word or Phrase That Best Completes Each Statement $A ( t ) = 200 \mathrm { e } ^ { - .048 t }$