Two bodies of masses 2 Kg and 7 Kg are moving with velocities of 2 m/s and 7 m/s respectively. What is the total momentum of the system in Kg-m/s?

Both the bodies are moving with constant velocity, hence both of them have momentum. The momentum of the system is the sum of the momenta of the bodies. 

Hence total momentum = 2 x 2 + 7 x 7 = 53 Kg-m/s.