Answer:
The answer is "[tex]\bold{6.6 \times 10^{12}\ years}[/tex]"
Step-by-step explanation:
Let the given value is:
[tex]R=\frac{1}{9^{17}}\\\\\to \frac{N_{c_{14}}}{N_{c_{12}}}=\frac{1}{9^{17}}\\\\\to t=\frac{2.303 \times 9^{17}}{5717}=6.6\times 10^{12}\ years[/tex]