Many dimensions – 2

Evaluate

$\displaystyle \int_0^1 \int_0^1 \cdots \int_0^1 (x_1 \times x_2 \times \cdots \times x_n) \, dx_1 dx_2 \cdots dx_n$

for $n=10$ .

The result can be expressed as $\frac 1 a$ . Submit $a$ .