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sat数学题 1.If it is now 4:00 p.m. Saturday, in hours from now, what time and day will it be? (Assume no daylight saving time changes in the period.) Answer Choices (A) 5:00 a.m. Saturday (B) 1:00 a.m. Sunday (C) 5:00 p.m. Tuesday (D) 1:00 a.m. Wednesday (E) 5:00 a.m. Wednesday 2.If , then Answer Choices (A) (B) (C) (D) (E) Read the following SAT test question and then click on a button to select your answer.
3.The function , defined for, is graphed above. For how many different values of is ?
Answer Choices (A) None (B) One (C) Two (D) Three (E) Four
4.In the figure above, O is the center of the circle and triangle ABO is equilateral. If the sides of triangle ABO are of length 6, what is the length of line BC? (A) 3 times square root 3 (B) 4 times square root 3 (C) 6 times square root 3 (D) 9 (E) 12 5.If the function is defined by , where , for which of the following values of is undefined?
Answer Choices (A) None (B) only (C) only (D) and only (E) , , and 6.If , then Answer Choices (A) (B) (C) (D) (E) 7.A jar contains only red marbles and green marbles. If a marble is selected at random from the jar, the probability that a red marble will be selected is . If there are 36 green marbles in the jar, how many red marbles are there in the jar? Answer Choices (A) 18 (B) 24 (C) 54 (D) 72 (E) 108 8.If is an odd integer, which of the following is an even integer? Answer Choices (A) (B) (C) (D) (E) Explanation 1.The correct answer is E Since each day has hours, it is a good idea to divide by to find the number of complete intervals in hours and the number of hours remaining after the intervals have been accounted for. When is divided by , the quotient is and the remainder is . The complete intervals tell you that days, or one full week plus days, go by, bringing you to Tuesday at 4:00 p.m. The additional hours take you into the next day, Wednesday. The hours will end at 5:00 a.m. on Wednesday. 2.The correct answer is C You are given that . Dividing both sides of the equation by gives. Thus, the answer is . 3.The correct answer is E when the point is on the graph of . Drawing the line , as in the graph below, shows that the is equal to for four values of between and . 4.The correct answer is C Choice (C) is correct. Since triangle ABO is equilateral, each of its angles has measure 60 degrees. It follows that angle BOC has measure 120 degrees. Since line OB and line OC are radii of the same circle, they are of equal length, and so delta OCB is isosceles. Hence angle OBC and angle OCB each have measure 30 degrees. Thus angle ABC has measure 60 degrees + 30 degrees = 90 degrees, and so triangle ABC is a 30 degrees minus 60 degrees minus 90 degrees right triangle. Since line AB, the side opposite the 30 degrees angle in triangle ABC, is of length 6, it follows that line BC, the side opposite the 60 degrees angle, is of length 6 times square root 3. 5.The correct answer is C If , then . If , then . If , then , which is not defined because division by is undefined. Therefore, of the three values, , , and , the only one for which is undefined is . Thus the correct response is only. 6.The correct answer is A The question states that . Solving for gives when the fraction is reduced. 7.The correct answer is D Choice (D) is correct. Let r be the number of red marbles in the jar. The probability of selecting a red marble is equal to the number of red marbles divided by the total number of marbles. Since the probability of selecting a red marble is , it follows that . There are 36 green marbles and r red marbles, so the previous equation becomes . This simplifies to2(r + 36) = 3r, or 2r + 72 = 3r. Therefore, the number of red marbles, r, is 72. 8.The correct answer is E If is an odd integer, then and are odd integers. Similarly, choices and are odd integers. Since an odd integer subtracted from another odd integer is always an even integer, is even.
以上就是这8道SAT数学练习题的全部内容，很简单。但是大家一定要记得，不要拿这些SAT数学练习题的难度和真正的SAT数学考试的难度相比，因为SAT数学考试的难度比这个要高，大家从中需要了解的是SAT数学考试的出题方式和相关词汇。 |
