Bromine-82 has a half of about 35 hours. After 140 hour, how many milliliters of an 80 mL sample will remain? A,65mL B.20mL C.10mL D.5mL

[tex]\bf \textit{Amount for Exponential Decay using Half-Life} \\\\ A=P\left( \frac{1}{2} \right)^{\frac{t}{h}}\qquad \begin{cases} A=\textit{accumulated amount}\\ P=\textit{initial amount}\to &80\\ t=\textit{elapsed time}\to &140\\ h=\textit{half-life}\to &35 \end{cases} \\\\\\ A=80\left( \frac{1}{2} \right)^{\frac{140}{35}}\implies A=80\left( \frac{1}{2} \right)^4[/tex]