The elevation in boiling point for 1 molal solution of non-volatile solute A is $3 \mathrm{~K}$. The depression in freezing point for 2 molal solution of $\mathrm{A}$ in the same solvent is 6 $K$. The ratio of $K_{b}$ and $K_{f}$ i.e., $K_{b} / K_{f}$ is $1: X$. The value of $X$ is [nearest integer]