Concept:In a perfectly inelastic collision, the two masses stick together and move with a common velocity. Linear momentum of the system is conserved because no external force acts during the collision.Explanation:Write the initial momentum of each mass separately along the X-axis and Y-axis.For mass M moving along X-axis with velocity Vi^:p1=M(Vi^)=MVi^For mass 2M moving along Y-axis with velocity 3Vj^:p2=2M(3Vj^)=6MVj^Total initial momentum of the system:pi=MVi^+6MVj^After sticking, the total mass becomes:M+2M=3MLet the common velocity after collision be v. Using conservation of linear momentum:3Mv=MVi^+6MVj^Divide both sides by 3M:v=3Vi^+2Vj^Answer:The velocity of the combination after the collision is 3Vi^+2Vj^, which is Option B.