The sum of all those terms which are rational numbers in the expansion of $\left(2^{1 / 3}+3^{1 / 4}\right)^{12}$ is:
$27$
$89$
$35$
$43$
Find the $r^{\text {th }}$ term from the end in the expansion of $(x+a)^{n}$
Coefficient of $x$ in the expansion of ${\left( {{x^2} + \frac{a}{x}} \right)^5}$ is
The coefficient of $x^{4}$ is the expansion of $\left(1+\mathrm{x}+\mathrm{x}^{2}\right)^{10}$ is
Find the coefficient of $a^{4}$ in the product $(1+2 a)^{4}(2-a)^{5}$ using binomial theorem.
Find the coefficient of $x^{6} y^{3}$ in the expansion of $(x+2 y)^{9}$