$A+B=76\\
A-B=38\ \ --->\ \ A=38+B\\\\
38+B+B=76\\
38+2B=76\ \ | subtract\ 38\\2B=38\ \ \ | divide\ by\ 2\\
B=19\\A=57\\\\
\frac{A}{B}=\frac{57}{19}=3$

3 0

3 years ago

Read 2 more answers

226Ra has a half-life of 1599 years. How much is left after 1000 years if the initial amount was 10 g?

Ray Of Light [21]

$\bf \textit{Amount for Exponential Decay using Half-Life}\\\\
A=P\left( \frac{1}{2} \right)^{\frac{t}{h}}\qquad 
\begin{cases}
A=\textit{accumulated amount}\\
P=\textit{initial amount}\to &10\\
t=\textit{elapsed time}\to &1000\\
h=\textit{half-life}\to &1599
\end{cases}
\\\\\\
A=10\left( \frac{1}{2} \right)^{\frac{1000}{1599}}$

8 0

3 years ago