Will someone please help me with this Physics question

So, for my high school Physics class, I have a take-home test that I am allowed to use basically limitless resources to complete. As a result, the questions are a bit harder than what has been discussed in class. Here is the question I am currently stuck on:

"While in Earth's orbit, an 80-kg. astronaut carrying a 20-kg. tool kit is initially drifting toward a stationary (to her) space shuttle at a speed of 2 m/s. If she throws the tool kit toward the shuttle with a speed of 6 m/s as seen from the shuttle, her final speed is:"

a) 1 m/s toward the shuttle c) 2 m/s toward the shuttle e) 6 m/s away from the shuttle
b) 1 m/s away from the shuttle d) 4 m/s toward the shuttle


I don't necessarily need the answer itself; I'm just having issues setting up the problem. I have tried a number of times using p=mv and the related. If someone could just kindly walk me through the process, I would be most appreciative.

Thank you very much! Peace,

Sarah x

This is just the law of conservation of momentum.

Measure all velocities relative to the shuttle. Take 'towards the shuttle' as the positive direction.

Initial momentum = total mass x velocity = (80+20) x 2 = 200kgm/s

After she throws the toolkit:
The momentum of the toolkit = 20 x 6 = 120kgm/s
Her velocity is v so her momentum = 80v
Total momentum after the throw = 120+80v

From the law of conservation of momentum.
Initial momentum = Final momentum
200 = 120+80v
80 = 80v
v = 1m/s
This is positive, so the direction is towards the shuttle; the answer is a).

m1/v1=m2/v2
80/2=20/6
40=????
ahhahaha idk