2017年10月20日SAT官方每日一题---数学选择.

　　为了让我们更好的适应sat考试，sat官网每天都会有sat官方每日一题，下面是小编为您整理的2015年10月sat官方每日一题，是数学选择，让我们一起来看一看这道数学选择吧。

　　Read the following SAT test question and then click on a button to select your answer.

　　In an 8-gram solution of water and alcohol, the ratio by mass of water to alcohol is 3 to 1. If 12 grams of a solution consisting of 2 grams water for each gram of alcohol is added to the 8-gram solution, what fraction by mass of the new solution is alcohol?

　　(A) 1/6

　　(B) 3/10

　　(C) 5/12

　　(D) 7/12

　　(E) 5/24

　　答案：B

　　解析：

　　To find what fraction by mass of the new solution is alcohol, you can find how many grams of alcohol are in the final solution of 20 grams. Since the 8-gram solution is 1 part alcohol to 3 parts water, it is 1/4 alcohol. So it contains 2 grams of alcohol. Similarly, the 12-gram solution is 1/3 alcohol by mass, so it contains 4 grams of alcohol. Thus, the final 20-gram solution contains 6 grams of alcohol, so 6/20, or 3/10, of it is alcohol.

　　上面是小编为您整理的2015年10月sat官方每日一题，是数学选择，为了让我们更好的适应sat考试，sat官网每天都会有sat官方每日一题，让我们一起来看一看这道数学选择吧。