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2013年9月28日SAT官方每日一题---数学选择

  下面是2013年9月28日的SAT官方每日一题的内容,是关于数学方面的,题型是选择。SAT官方每日一题是collegeboard每天都会发布的题目,关于SAT考试的三个部分的各个题型。大家和无忧小编一起来看一下这个SAT官方每日一题吧。

  SAT官方每日一题之数学---选择:

  Mathematics > Standard Multiple Choice

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

  If(5 times x) minus 3 = 2 times a, then((5 times x) minus 3) over 2 =

  (A)a over 4

  (B)a over 2

  (C)a

  (D)2 times a

  (E)4 times a

  The correct answer is C

  Explanation

  You are given that(5 times x) minus 3 = 2 times a. Dividing both sides of the equation by2gives((5 times x) minus 3) over 2 = a. Thus, the answer isa.

  下面为大家提供一些和这些SAT官方每日一题相似的题目,供大家练习:

graphic

 

  The histogram above shows the distribution of 31 black cherry trees, by height. For example, the leftmost bar represents the black cherry trees that are at least 60 feet, but not less than 65 feet, in height. Based on the histogram, which of the following can be the average (arithmetic mean) height of the 31 black cherry trees?

  Answer Choices

  (A) 70 feet

  (B) 72 feet

  (C) 74 feet

  (D) 78 feet

  (E) 80 feet

  The correct answer is C

  Explanation

  The histogram does not give the recorded heights for each cherry tree, but rather the intervals in which the heights lie. Thus, to find possible values for the average (arithmetic mean) height, one can find lower and upper bounds for the average height by calculating the averages of lower and upper interval bounds of the histogram with the frequencies given. A lower bound for the average, found by using the value at the left endpoint of the interval, is ((60 times 3) + (65 times 3) + (70 times 8) + (75 times 10) + (80 times 5) + (85 times 2)) over 31 is approximately equal to 72.74feet, and so 72.74 + 5 = 77.74feet would be an upper bound for the average height. Therefore, the average height of the 31 black cherry trees can be between 72.74 feet and 77.74 feet. Of the choices given, only 74 feet can be a possible value for the average height of the 31 black cherry trees.

  以上就是关于2013年9月28日SAT官方每日一题中数学部分的详细内容,包括了题目和选项以及答案,后面附有一道相关的练习题。大家可以在备考SAT的过程中关注SAT每日一题的内容,这样就可以更好有不间断的练习,也就能在日积月累的过程中得到提高。