C-10-Q050: In the expansion of $(1+3x)^5$, the coefficient of $x^2$ is —

C-10-Q050: In the expansion of $(1+3x)^5$, the coefficient of $x^2$ is — | প্রশ্ন করি

In the expansion of (1+3x)5(1+3x)^5(1+3x)5, the coefficient of x2x^2x2 is —