[求助]请教几道PREP数学题,没找到讨论

194.
                20990-!-item-!-187;#058&013496

A certain state levies a 4 percent tax on the nightly rates of hotel rooms.  A certain hotel in this state also charges a $2.00 nightly fee per room, which is not subject to tax.  If the total charge for a room for one night was $74.80, what was the nightly rate of the room?

(A) $68.00

(B) $69.00

(C) $70.00

(D) $71.00

(E) $72.00

A set of 15 different integers has a median of 25 and a range of 25.  What is the greatest possible integer that could be in this set?

(A) 32

(B) 37

(C) 40

(D) 43

(E) 50

132.
                    13505-!-item-!-187;#058&009469

If d is the standard deviation of x, y, and z, what is the standard deviation of x + 5, y + 5, and z + 5 ?

(A) d

(B) 3d

(C) 15d

(D) d + 5

(E) d + 15

121.
                    12439-!-item-!-187;#058&008408

[?]

A vending machine is designed to dispense 8 ounces of coffee into a cup.  After a test that recorded the number of ounces of coffee in each of 1,000 cups dispensed by the vending machine, the 12 listed amounts, in ounces, were selected from the data.  If the 1,000 recorded amounts have a mean of 8.1 ounces and a standard deviation of 0.3 ounce, how many of the 12 listed amounts are within 1.5 standard deviations of the mean?

(A) Four

(B) Six

(C) Nine

(D) Ten

(E) Eleven

106.
                    11122-!-item-!-187;#058&007588

If a certain sample of data has a mean of 20.0 and a standard deviation of 3.0, which of the following values is more than

2.5 standard deviations from the mean?

(A) 12.0

(B) 13.5

(C) 17.0

(D) 23.5

(E) 26.5

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

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

43.   5768-!-item-!-187;#058&004705

A committee of three people is to be chosen from four married couples.  What is the number of different committees that can be chosen if two people who are married to each other cannot both serve on the committee?

(A)  16

(B)  24

(C)  26

(D)  30

(E)  32

不好意思这么多,有懂的战友帮帮忙吧,先谢谢大家!

194. C (问题应该是nightly fee吧，如果是rate，那答案应该是比率了)

139. D

132. A

43. E

还有几道我想想，先吃午饭～－－0

先确定答案。。。。lz

7.51 8.22 7.86 8.36
8.09 7.83 8.30 8.01
7.73 8.25 7.96 8.53

121的条件。。。