Incorrect. This problem tells you that $\displaystyle{N}=\frac{{k}}{{C}}\usepackage{cmbright}\Huge\$ , for some constant k. Substituting the given information gives you: $\displaystyle{9}=\frac{{k}}{{8}}\usepackage{cmbright}\Huge\$

Find k and use this with the new value of C to find the new value of N.