Not sure if this is precalc but its at the end of my trig book anyways:

I get : $\displaystyle \frac {_7 C_4 * _5C_3 *_1_0 C_1}{_2_2 C_8}$ $\displaystyle \Rightarrow$ $\displaystyle \frac {35*10*10}{58198140}$

Which does not equal the book answer of $\displaystyle \frac {350}{31977}$

What is my error?