The work functions of two metals $\left(M_A\right.$ and $\left.M_B\right)$ are in the $1: 2$ ratio. When these metals are exposed to photons of energy 6 eV , the kinetic energy of liberated electrons of $M_A: M_B$ is in the ratio of $2.642: 1$. The work functions (in eV ) of $M_A$ and $M_B$ are respectively.