**Question:**

If the coefficients of $\mathrm{x}^{2}$ and $\mathrm{x}^{3}$ are both zero, in the expansion of the expression $\left(1+a x+b x^{2}\right)(1-3 x)^{15}$ in powers of $x$, then the ordered pair $(a, b)$ is equal to:

Correct Option: 3

JEE Main Previous Year April 10, 2019(I)

**Solution:**