A solid sphere and a hollow cylinder roll up without slipping on same inclined plane with same initial speed $v$. The sphere and the cylinder reaches upto maximum heights $h _ { 1 }$ and $h _ { 2 }$, respectively, above the initial level. The ratio $h _ { 1 } : h _ { 2 }$ is $\frac { n } { 10 }$. The value of $n$ is $\_\_\_\_$.