Two uncharged metal balls, X and Y, stand on glass rods, and are in touch with each other. A third ball Z carrying a negative charge, is brought near...

Two uncharged metal balls, X and Y, stand on glass rods, and are in touch with each other. A third ball Z carrying a negative charge, is brought near the first two (closer to Y). While the positions of these balls are fixed, ground the ball X and then break the grounding. While X and Y remain in touch, remove Z. Then separate X and Y. What are the charges on each of the balls?