If a baseball is thrown 30 m/s backwards from a truck moving 50 m/s, how fast will the ball strike the glove of a ground-based catcher?

Is the 30 m/s throw with respect to the truck? I will assume so. The ball will move in the direction of the truck's motion, at 20 m/s. Which direction is the catcher facing? He would have to be ahead of the truck when it is thrown

Are you sure you copied the truck's speed correctly? 50 m/s is about 112 mph.