$$\frac { \log _ { 10 } a } { 2 } = \frac { \log _ { 10 } b } { 3 } = \frac { \log _ { 10 } c } { 5 } b c =$$
$\frac{\log(a)}{2}=\frac{\log(b)}{3}\text{ and }\frac{\log(b)}{3}=\frac{bc\log(c)}{5}$
