Two balls are placed near one another and hang down, as shown below. which conclusion is supported by this evidence? neither ball has a charge. the balls are both positively charged. one ball is positively charged, and the other is negatively charged. each ball has a charge, but the type of charge is unknown.

Working alone at its constant rate, pump x pumped out ¼ of the water in a tank in 2 hours. then pumps y and z started working and the three pumps, working simultaneously at their respective constant rates, pumped out the rest of the water in 3 hours. if pump y, working alone at its constant rate, would have taken 18 hours to pump out the rest of the water, how many hours would it have taken pump z, working alone at its constant rate, to pump out all of the water that was pumped out of the tank? a) 6b) 12c) 15d) 18e) 24