Question

An element with a mass 330 grams decays by 25.5% per minute.How much of the element is remaining after 5 minutes, to the nearest 10th of a gram.

Answer 1

75.6

Explanation:

Answer 2

`\bf \qquad \textit{Amount for Exponential Decay} \\\\ A=P(1 - r)^t\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\dotfill &330\\ r=rate\to 25.5\%\to (25.5)/(100)\dotfill &0.255\\ t=\textit{elapsed time}\dotfill &5\\ \end{cases} \\\\\\ A=330(1-0.255)^5\implies A=330(0.745)^5 \\\\\\ A\approx 75.7347687\implies \stackrel{\textit{rounded up}}{A=75.7}`