A bullet of mass 10.0 gram moving at a velocity of 397 m/s toward the right strikes an orange of mass 90.0 gram. The bullet passes through the orange and in the process pulls out 10.0 grams of orange innards. Assuming that this collision is elastic (i.e., that no kinetic energy is lost), what is the velocity of the rest of the remaining 80 grams of orange? Take rightward motion to be positive and leftward motion to be negative.

Hint: It is easiest to do these problem if you first shift to the center of mass frame of the orange & bullet, determine the velocities of both objects after the collision in that frame, and then shift back to the "lab" frame.