To calculate the doubling time, you can use the Rule of 70, which is a way to estimate the time it takes for a quantity to double at a constant growth rate. The formula is:
[tex]\[
\text{Doubling Time} = \frac{70}{r}
\][/tex]
where [tex]\( r \)[/tex] is the growth rate expressed as a percentage.
Given that the growth rate [tex]\( r \)[/tex] is 35%, you need to first convert this percentage into a decimal, which is done by dividing by 100:
[tex]\[
r = 35\% = \frac{35}{100} = 0.35
\][/tex]
Now, substitute [tex]\( r \)[/tex] into the doubling time formula:
[tex]\[
\text{Doubling Time} = \frac{70}{0.35}
\][/tex]
Perform the division:
[tex]\[
\text{Doubling Time} = 200
\][/tex]
Therefore, the doubling time is 200 years. The correct answer is:
[tex]\[
200 \text{ years}
\][/tex]