问题
单项选择题
The ratio，by volume, of soap to alcohol to water in a certain solution is 2:50:100. The solution will be altered so that the ratio of soap to alcohol is doubled while the ratio of soap to water is halved. If the altered solution will contain 100 cubic centimeters of alcohol, how many cubic centimeters of water will it contain ？（）
A．50
B．200
C．400
D．625
E．800
答案
参考答案：E
解析：
根据肥皂和酒精比率加倍，而肥皂与水的比率减半可得改变后的溶液中肥皂、酒精与水体积比为4:50:400。而酒精的体积等于100立方厘米，所以水的体积为100×8=800立方厘米。