lets assume the right direction as positive direction of motion and left direction as negative direction of motion
m₁ = 0.200 kg
v₁ = velocity of m₁ before collision= 0.750 m/s
v'₁ = velocity of m₁ after collision= - 0.250 m/s
m₂ = 0.200 kg
v₂ = velocity of m₂ before collision= 0 m/s
v'₂ = velocity of m₂ after collision= ?
using conservation of momentum
m₁ v₁ + m₂ v₂ = m₁ v'₁ + m₂ v'₂
(0.200) (0.750) + (0.400) (0) = (0.200) (- 0.250) + (0.400) v'₂
v'₂ = 0.500 m/s
so the glider of mass m₂ moves right at speed of 0.500 m/s