SAT官方每日一题 2017年4月28日.

SAT试题类型 Mathematics > Standard Multiple Choice Read the following SAT test question and then click on a button to select your answer. (1 over 2) times (2 over 3) times (3 over 4) times (4 over 5) times (5 over 6) times (6 over 7) = Answer Choices (A) 1 over 7 (B) 3 over 7 (C) 21 over 27 (D) 6 over 7 (E) 7 over 8 答案：A 解析： Explanation If a question looks as if it requires a lot of calculating, that’s often a tip-off that something else is going on. There’s usually a quick way to find the answer. In this question, all the fractions are being multiplied and so canceling is a possibility. The denominators cancel diagonally with the numerators that follow. The 2 from 1 over 2 cancels with the 2 from 2 over 3. The 3 from 2 over 3 cancels with the 3 from 3 over 4. And so on, right down to the equal sign. After you have canceled everything that can be canceled, you are lt with the fraction 1 over 7.