A bady of mass $M_1=4 kg$ moves at $5 \hat i$ m/s and another body of mass $m_2=2 kg$ moves at $10 \hat i$m/s. The kinetic energy of center of mass is :

Question

$$\begin {array} {1 1} (1)\;\frac{200}{3}\;J & \quad (2)\;\frac{500}{3}\;J \\ (3)\;\frac{400}{3}\;J & \quad (4)\;\frac{800}{3} J \end {array}$$