Truly multivariable

Given the vector $\vec{V} \left \langle 1,2,3,4,...,23,24 \right \rangle$ in 24-space, find the sum of all the directional cosines. If the sum of all directional cosines can be represented in the form $\dfrac{a}{b}$ , where $a$ and $b$ are relatively prime, find $a+b$ .