$^{10}{C_1}{ + ^{10}}{C_3}{ + ^{10}}{C_5}{ + ^{10}}{C_7}{ + ^{10}}{C_9} = $
${2^9}$
${2^{10}}$
${2^{10}} - 1$
None of these
If ${\left( {1 + x} \right)^n} = {c_0} + {c_1}x + {c_2}{x^2} + {c_3}{x^3} + ...... + {c_n}{x^n}$ , then the value of ${c_0} - 3{c_1} + 5{c_2} - ........ + {( - 1)^n}\,(2n + 1){c_n}$ is
Co-efficient of $\alpha ^t$ in the expansion of,
$(\alpha + p)^{m - 1} + (\alpha + p)^{m - 2} (\alpha + q) + (\alpha + p)^{m - 3} (\alpha + q)^2 + ...... (\alpha + q)^{m - 1}$
where $\alpha \ne - q$ and $p \ne q$ is :
The sum, of the coefficients of the first $50$ terms in the binomial expansion of $(1-x)^{100}$, is equal to
If $\sum\limits_{r = 0}^{25} {\left\{ {^{50}{C_r}.{\,^{50 - r}}{C_{25 - r}}} \right\} = K\left( {^{50}{C_{25}}} \right)} $, then $K$ is equal to
${C_1} + 2{C_2} + 3{C_3} + 4{C_4} + .... + n{C_n} = $