If $C_0, C_1, C_2, \ldots, C_{10}$ represent the binomial coefficients in the expansion of $(1+x)^{10}$, then

$$ C_0 C_6+C_1 C_7+C_2 C_8+C_3 C_9+C_4 C_{10}= $$

When $|x|<\frac{1}{2}$ the coefficient of $x^6$ in the expansion of $\left(\frac{2-x}{1+2 x}\right)^2$ is

If $C_0, C_1, C_2, \ldots, C_n$ are the binomial coefficients in the expansion of $(1+x)^n$ then the value of $\Sigma r^3 \cdot C_r$ when $n=5$ is

The coefficient of $x^{12}$ in the expansion of $\left(x^2+2 x+2\right)^8$ is