In inelastic collision momentum remains conserved.
Macroscopic collisions are generally inelastic and do not conserve kinetic energy, though ofcourse the total energy is conserved. The extreme inelastic collision is one in which the colliding objects stick together after collision.
From conservation of momentum, we have m1v1+m2v2=(m1+m2)v
Given, m1=a,v1=b,m2=c,v2=0 ∴a⋅b+c⋅0=(a+c)v ⇒v=a+cab