\(M_{A}=0.2 \mathrm{kg}\) and \(M_{B}=0.5 \mathrm{kg}\)

Velocity of \(A\) and \(B\)

From the conservation of momentum 

\(M_{A} V_{A}+M_{B} V_{B}=M_{t o t a l} V_{c m}\)

\(V_{\sigma m}=\frac{M_{A} V_{A}+M_{B} V_{B}}{M_{t o t a l}}=\frac{0.2(10 \hat{i})+0.5(3 \hat{i}+5 \hat{j})}{0.2+0.5}\)

\(V_{c m}=5 \hat{\imath}+\frac{25}{7} \hat{\jmath}\)

Velocity of center of mass \(5 \hat{\imath}+\frac{25}{7} \hat{j}\)