SAT官方数学习题 8月31日

Correct Answer: B

• Here's Why:

  Consider each statement separately. For example, consider statement I, AB + CD = AD. From the figure, you can see that segment AD is made up of the segments AB, BC, and CD. This tells you that AB + CD cannot equal AD, since BC cannot equal zero. Statement I is not true.

  Consider statement II, AB + BC = AD – CD. Since B is between A and C, it follows that AB + BC = AC. Since C is between A and D, it follows that AC + CD = AD. Therefore, AD – CD = AC. Since both AB + BC and AD – CD equal AC, they are equal to each other. Statement II is true.

  Consider statement III, AC – AB = AD – CD. The left side of the equation, AC – AB, is equivalent to BC. The right side of the equation, AD – CD, is equivalent to AC. Since AB cannot equal zero, BC is not equal to AC. Statement III is not true.

  Statement II is the only one that is true.

• Difficulty: Medium
• Question Type: Standard Multiple Choice