The tsunami that hit japan in march of 2011 illustrates which of the following points? a. most countries are unprepared for tsunamis. b. tsunamis can cause many kinds of destruction. c. more people are killed by tsunamis than earthquakes each year. d. it is rare that modern nations need to be concerned about tsunamis .

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