Answer:
The magnitude of the change of velocity the 5-kg ball experiences is less than that of the 10-kg ball.
Explanation:
In inelastic collision, the total momentum is always conserved after collision but the kinetic energy is reduced.
Momentum is Mass X velocity.
5 kg ball is in motion, while 10 kg ball is stationary; that is zero velocity.
The momentum of 10 kg ball before collision is zero while the momentum of 5 kg ball before collision is more than zero. Therefore, the magnitude of change in momentum will not be equal.
Next possible options are in kinetic Energy
Initial Kinetic energy = 
Final kinetic energy =
Change in kinetic energy = Final Kinetic Energy - Initial Kinetic Energy
Change in kinetic energy of 5kg ball = 
Since the 5-kg ball has initial velocity (u), the magnitude of the change in velocity will be reduced.
Change in kinetic energy of 10kg ball:
the ball is initially at rest, therefore the initial velocity (u) will be zero (0)
Δ K.E = 
From the solution above, the magnitude of the change in velocity experienced by 10 kg ball is higher than 5 kg ball.
Hence, The magnitude of the change of velocity the 5-kg ball experiences is less than that of the 10-kg ball