两道SAT数学练习题解析

2022-05-28 09:12:50

  下面为大家推荐的适当两道

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

  1、A woman drove to work at an average speed of miles per hour and returned along the same route at miles per hour. If her total traveling time was hour, what was the total number of miles in the round trip?

  Answer Choices

  (A)

  (B)

  (C)

  (D)

  (E)

  The correct answer is C

  Explanation

  Let represent the time it took the woman to drive to work. Since her total traveling time was hour, the time it took her to return home is . The distance in miles can be found using the formula . The distance traveled to work is , and the return distance is . Since the distance to work is the same as the return distance, . Solving for yields . So the distance one way is miles. The total number of miles in the round trip is , or miles.

  2、

  If two sides of the triangle above have lengths and , the perimeter of the triangle could be which of the following?

  Answer Choices

  (A)only

  (B) only

  (C) only

  (D) and only

  (E) , , and

  The correct answer is B

  Explanation

  Difficulty: Hard

  In questions of this type, statements , , and should each be considered independently of the others. You must determine which of those statements could be true.

  Statement cannot be true. The perimeter of the triangle cannot be , since the sum of the two given sides is without even considering the third side of the triangle.

  Continuing to work the problem, you see that in , if the perimeter were , then the third side of the triangle would be , or . A triangle can have side lengths of , , and . So the perimeter of the triangle could be .

  Finally, consider whether it is possible for the triangle to have a perimeter of . In this case, the third side of the triangle would be . The third side of this triangle cannot be , since the sum of the other two sides is not greater than. By the Triangle Inequality, the sum of the lengths of any two sides of a triangle must be greater than the length of the third side. So the correct answer is only.

  以上就是这两道SAT数学练习题的全部内容,来自SAT考试官方网站collegeboard。大家可以在备考SAT数学考试的时候,多加练习,以便更好更快的掌握考试的答题方法和技巧。

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