SAT数学每日一练 12月8日.

下面是一道SAT数学练习题，答案在下一页，请自行完成后参看答案和解析。

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

A 25-foot ladder is placed against a vertical wall of a building, with the bottom of the ladder standing on concrete 7 feet from the base of the building. If the top of the ladder slips down 4 feet, then the bottom of the ladder will slide out

A.4 feet

B.5 feet

C.6 feet

D.7 feet

E.8 feet

Correct Answer: E

Here&aposs Why:

The ladder, the wall, and the ground form a right triangle with a 25-foot hypotenuse. At first, the bottom of the ladder is 7 feet from the base of the building, so one leg of the right triangle measures 7 feet; the length of the other leg, x, can be found by solving 72 + x2 = 252, which is the Pythagorean theorem. From this, you can figure out that the other leg measures 24 feet.

After the ladder slips down 4 feet, the 24-foot leg of the right triangle becomes 20 feet long. The other leg then has to be 15 feet long. This length is found by solving 202 + y2 = 252, which is again the Pythagorean theorem.

Since the distance between the bottom of the ladder and the base of the building increases from 7 feet to 15 feet, the amount that the bottom of the ladder slides out is 8 feet.

Difficulty: Hard

Question Type: Standard Multiple Choice(Mathematics)

下面是一道SAT数学练习题，答案在下一页，请自行完成后参看答案和解析。

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

A 25-foot ladder is placed against a vertical wall of a building, with the bottom of the ladder standing on concrete 7 feet from the base of the building. If the top of the ladder slips down 4 feet, then the bottom of the ladder will slide out

A.4 feet

B.5 feet

C.6 feet

D.7 feet

E.8 feet

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