The sum of coefficients of integral power of $x$ in the binomial expansion ${\left( {1 - 2\sqrt x } \right)^{50}}$ is :
$\frac{1}{2}\left( {{2^{50}} + 1} \right)$
$\;\frac{1}{2}\left( {{3^{50}} + 1} \right)$
$\;\frac{1}{2}\left( {{3^{50}}} \right)$
$\;\frac{1}{2}\left( {{3^{50}} - 1} \right)$
The value of ${\sum\limits_{r = 1}^{19} {\frac{{{}^{20}{C_{r + 1}}\left( { - 1} \right)}}{{{2^{2r + 1}}}}} ^r}$ is
The sum of the co-efficients of all odd degree terms in the expansion of ${\left( {x + \sqrt {{x^3} - 1} } \right)^5} + {\left( {x - \sqrt {{x^3} - 1} } \right)^5},\left( {x > 1} \right)$
The sum of coefficients in ${(1 + x - 3{x^2})^{2134}}$ is
The coefficient of $x^8$ in the expansion of $(x-1) (x- 2) (x-3)...............(x-10)$ is :
If number of terms in the expansion of ${(x - 2y + 3z)^n}$ are $45$, then $n=$