Momentum problems

A gun has a mass of 10 kilograms and its bullet has a mass of 20 grams.  Suppose that the bullet fires out of the bun barrel with a speed of 300 m/s (about 600 miles per hour).  What is the recoil speed of the gun? ________ m/s

A ball of mass 200 grams (a softball, perhaps) is moving at 3 m/s before it collides head-on with a baseball of mass 150 grams.  After the collision, the baseball is moving forward at a speed of 2.5 m/s.  How fast is the softball moving after collision? (Hint: You may use grams as your unit of mass here as long as you use it on both sides of the equation.) __________ m/s