Browse Questions

# For $| x | < \large\frac{1}{5}$, the coefficient of $x^3$ in the expansion of $\large\frac{1}{(1-5x)(1-4x)}$ is :

$\begin {array} {1 1} (1)\;369 & \quad (2)\;370 \\ (3)\;371 & \quad (4)\;372 \end {array}$

(a) 369