Density of a liquid in CGS system is $0.625 g/c{m}^3$  . What is its magnitude in SI system

1 CGS       SI

$N_1{U}_1=N_2{U}_2$

$N_1\left[M_1{L}_1^{-3}\right]=N_2[M_2{L}_2^{-3}$

$\therefore N_2=N_1\left[\frac{M_1}{M_2}\right]\times {\left[\frac{L_1}{L_2}\right]}^{-3}$

$=0.625\left[\frac{1g}{1kg}\right]\times {\left[\frac{1cm}{1m}\right]}^{-3}$

$=0.625\times {10}^{-3}\times {10}^6=625$