Calculate the Impulse

How do I do this??

A ball of mass 0.120 kg is dropped from rest from a height of 1.25 m. It
rebounds from the floor to reach a height of 0.600 m. What impulse was given
to the ball by the floor?
a) 1.01 kg m/s
b) 2.68 kg m/s
c) 4.29 kg m/s
d) 6.57 kg m/s
e) 7.41 kg m/s

impulse = change in momentum
size of momentum = mV {where m = mass = 0.120 kg, V = speed}
because momentum is a vector quantity {direction change is taken into account}
for any object dropped from rest which free-falls 1.25 m,
its speed = V=√2gh = √[19.6(1.25)] = √24.5 = 4.95 m/s as it reaches floor on drop
If it rebounds (assume *vertical* rebound) to a height of 0.600 m,
it had a speed = √2gh = √19.6(0.6) = √11.76 = 3.43 m/s as it starts upward from floor
the momentum of ball at floor upon drop = 4.95m downward
the momentum of ball at floor upon rebound = 3.43m upward
the impulse = change in momentum = 4.95m + 3.43m = 8.38m = 1.01 N-s ANS a)
{the reason these two momentua are added is that their directions and hence math signs are *opposite* so when subtracted to find change, their numbers are added}