问几个prep1的数学题哈 prep一塌糊涂...一塌糊涂..一塌糊涂.一塌糊涂

lbccd

1.For all positive integers m,m = 3m when m is odd and m = 1/2 m when m is even.Which of the following is equivalent to 9 x 6?
(A)81
(B)54
(C)36
(D)27
(E)18
呃...这题回了 即么艾西真阴险!!! 鄙视

2.Malik's recipe for 4 servings of a certain dish requires 1.5 cups of pasta.According to this recipe, what is the number of cups of pasta that Malik will use the next time he prepares this dish?
1.The next time he prepares this dish, Malik will make as many servings as he did the last time he prepared the dish.
2.Malik used 6 cups of pasta the last time he prepared this dish.

3..还有1题..说的是有条直线 问什么时候intersect 第2象限 ds题
1.斜率是-(1/6)
2.y轴截距是-6
这单1怎么能定呢....


4...is the integer x divisible by 6
1.x+3 is divisible by 3
2.x+3 is an odd number


5..in the xy-plane, at what two points does the graph of y=(x+a)(x+b)intersect the x-axis?
1.a+b=-1
2.the graph intersects the y-axis at (0,-6)

6....
Martha bought an armchair and a coffee table at an auction and sold both items at her store.Her gross profit from the purchase and sale of the armchair was what percent greater than her gross profit from the purchase and sale of the coffee table?
(1)Martha paid 10 percent more for the armchair than for the coffee table.
(2)Martha sold the armchair for 20 percent more than she sold the coffee table.

7...Are at least 10 percent of the people in Country X who are 65 years old or older employed?
(1) In Country X, 11.3 percent of the population is 65 years old or older.
(2) In Country X, of the population 65 years old or older, 20 percent of the men and 10 percent of the women are employed.


8....                    r      s   t
On the number line shown, is zero halfway between r and s ?
(1) s is to the right of zero.
(2) The distance between t and r is the same as the distance between t and -s.


dcacc ebc

sdcar2010

1. (9) = 27; (6) = 3; so (9)*(6) = 27 * 3 = 81
   (d) (27) = 81

sdcar2010

For 2, the answer is C since you need both conditions to nail down the amount of pasta  that would be needed.

sdcar2010

3..还有1题..说的是有条直线 问什么时候intersect 第2象限 ds题
1.斜率是-(1/6)
2.y轴截距是-6
这单1怎么能定呢....

The only time a line won't pass the Quadrant II is when the line is parallel to x axis and its y intercept is smaller than 0.  Basically they are lines like y = n; n<0.

sdcar2010

4...is the integer x divisible by 6
1.x+3 is divisible by 3
2.x+3 is an odd number

You need both 2 and 3 as factors in order to be devisible by 6. None of the condition fulfills both conditions.  Even the combinations won't help.  It's just uncertain.  If changed to x+3 is an even number, then the combination would work.

sdcar2010

5..in the xy-plane, at what two points does the graph of y=(x+a)(x+b)intersect the x-axis?
1.a+b=-1
2.the graph intersects the y-axis at (0,-6)

From 2, you got -6 = ab.  If you know a + b = -1, then a =2, b = -3.  x intercepts are (-2, 0) and (3, 0).

sdcar2010

7...Are at least 10 percent of the people in Country X who are 65 years old or older employed?
(1) In Country X, 11.3 percent of the population is 65 years old or older.
(2) In Country X, of the population 65 years old or older, 20 percent of the men and 10 percent of the women are employed.

From 2, you know that at least 10% of 65+ are employed unless there are people who has no sex.

sdcar2010

8....                    r      s   t
On the number line shown, is zero halfway between r and s ?
(1) s is to the right of zero.
(2) The distance between t and r is the same as the distance between t and -s.

From 2, if s is positive, then r is -s and the (0) is between r and s. if s is negative, then the (0) is to the right of t.

Therefore, combining 1) and 2), the zero is halfway between r and s.

johnson1120

刚刚俺也prep了一把，可怜的600......

lbccd

1. (9) = 27; (6) = 3; so (9)*(6) = 27 * 3 = 81
   (d) (27) = 81

-- by 会员 sdcar2010 (2010/12/22 22:48:50)

恩恩 这个明白啦 谢谢啦~