标题: 马上就要考试啦！求数学2道题解释？ [打印本页] 作者: lvsheng0907 时间: 2012-5-30 13:40 标题: 马上就要考试啦！求数学2道题解释？ If the speed of x meters per second is equivalent to the speed of y kilometers per hour, what is y in terms of x ?
Pumps A, B, and C operate at their respective constant rates. Pumps A and B, operating simultaneously, can fill a certain tank in 6/5 hours; pumps A and C, operating simultaneously, can fill the tank in 3/2 hours; and pumps B and C, operating simultaneously, can fill the tank in 2 hours. How many hours does it take pumps A, B, and C, operating simultaneously, to fill the tank? (A) 1/3 (B) 1/2 (C) 2/3 (D) 5/6 (E) 1