The ratio of the coefficient of $x ^ { 15 }$ to the term independent of $x$ in the expansion of $\left( x ^ { 2 } + \frac { 2 } { x } \right) ^ { 15 }$ is: (1) $7 : 16$ (2) $7 : 64$ (3) $1 : 4$ (4) $1 : 32$
The ratio of the coefficient of $x ^ { 15 }$ to the term independent of $x$ in the expansion of $\left( x ^ { 2 } + \frac { 2 } { x } \right) ^ { 15 }$ is:\\
(1) $7 : 16$\\
(2) $7 : 64$\\
(3) $1 : 4$\\
(4) $1 : 32$