When two resistance $\mathrm{R_1}$ and $\mathrm{R_2}$ connected in series and introduced into the left gap of a meter bridge and a resistance of 10 $\Omega$ is introduced into the right gap, a null point is found at 60 cm from left side. When $\mathrm{R_1}$ and $\mathrm{R_2}$ are connected in parallel and introduced into the left gap, a resistance of 3 $\Omega$ is introduced into the right gap to get null point at 40 cm from left end. The product of $\mathrm{R_1}\mathrm{R_2}$ is $\underline{\hspace{2cm}}$$\Omega^2$