Under the same reaction conditions, initial concentration of $1.386 \mathrm{~mol} \mathrm{dm}^{-3}$ of a substance becomes half in 40 seconds and 20 seconds through first order and zero order kinetics, respectively. Ratio $\left(\frac{\mathrm{k}_1}{\mathrm{k}_0}\right)$ of the rate constants for first order $\left(\mathrm{k}_1\right)$ and zero order $\left(\mathrm{k}_0\right)$ of the reactions is