马上考了，求助prep1的ps题，麻烦大家解答，谢谢！

48.   6225-!-item-!-187;#058&004914

A certain city with a population of 132,000 is to be divided into 11 voting districts, and no district is to have a population that is more than 10 percent greater than the population of any other district.  What is the minimum possible population that the least populated district could have?

(A) 10,700

(B) 10,800

(C) 10,900

(D) 11,000

(E) 11,100

这题答案是D，我算不出答案来...

At the end of the first quarter, the share price of a certain mutual fund was 20 percent higher than it was at the beginning of the year.  At the end of the second quarter, the share price was 50 percent higher than it was at the beginning of the year. What was the percent increase in the share price from the end of the first quarter to the end of the second quarter?

(A) 20%

(B) 25%

(C) 30%

(D) 33%

(E) 40%

这题选B，但我不会算...

88.   10039-!-item-!-187;#058&007071

At a certain college there are twice as many English majors as history majors and three times as many English majors as mathematics majors.  What is the ratio of the number of history majors to the number of mathematics majors?

(A) 6 to 1

(B) 3 to 2

(C) 2 to 3

(D) 1 to 5

(E) 1 to 6

此题选C，可我算得B，麻烦大牛们解答，谢谢！

96.   10591-!-item-!-187;#058&007292

According to the directions on a can of frozen orange juice concentrate, 1 can of concentrate is to be mixed with 3 cans of water to make orange juice.  How many 12-ounce cans of the concentrate are required to prepare 200 6-ounce servings of orange juice?

(A)  25

(B)  34

(C)  50

(D)  67

(E)  100

此题答案是A，计算的式子应该是怎样的呢？

142.
                    14580-!-item-!-187;#058&010013

The rate of a certain chemical reaction is directly proportional to the square of the concentration of chemical A present and inversely proportional to the concentration of chemical B present.  If the concentration of chemical B is increased by 100 percent, which of the following is closest to the percent change in the concentration of chemical A required to keep the reaction rate unchanged?

(A) 100% decrease

(B) 50% decrease

(C) 40% decrease

(D) 40% increase

(E) 50% increase

这题答案是D，我选E。。。

48 设要求的数为n 那么 1.1n>=(132000-n)/10 n>=11000

85 1.5/1.2 -1=0.25

96 (1/4 *200 *6) /12

142 因为设square，所以A的比例 X^2 ； B的是 1/X  原来的A与B之比就是X^3

如果B翻一倍 (nX)^2/(2/X)=X^3 那么n^2=2 n=1.4 所以最后A增加大约40%

非常感谢楼上的各位！！~~我明白多啦~~88题是得B，不好意思答案看错了，谢谢楼上~