北美4月16 - 710(M50V36)

sy1103mstr · 发表于 2008-4-17 05:29:00

Math old JJ: #8 (eclipse area), #11 (ccircle), #15, #16, #30, #35, #39,
#53 (variant: the questions shows the result is 350 for all the digits
of number 10^n - 52, show n=?), #63,

One math question: ask if x > x2?
1). x > 0. 2), x > 1
f(x) = x - x2 = x(x-1) > 0 ==> x > 1 or 0 < x < 1
therefore, if x > 1, it is clearly that f(x) > 0, so the answer is B.

Another math question: which number is most closest to 1/2? choices are: 4/7, 5/9, 6/11, 6/13, 9/16
solution:
calculate the result of each number substract 1/2, and the result is
obvious, should be the 6/13 one (that one results in 1/26), which is
the smallest among all the substrated results.

another one is
similar to #93, but the question is: seniors only (20), chemistry only
(xx), there is a condition says the total chemistry students are
something, from which we can know that the common area of (senior and
chemistry) is 4, ask: what percenatge of seniors are in chemistry? 4/24
= 16.67%

sy1103mstr · 发表于 2008-4-17 06:31:00

more coming...

nick092123 · 发表于 2008-4-17 06:58:00

顶!

sy1103mstr · 发表于 2008-4-17 08:03:00

#101, #141 (attention: the quetion is if mn >=0, not as the in JJ of mn > 0), so the answer should be C (which means both sets have just one element, and the element times itself, mn = m^2 >= 0).

another question: 3 numbers, 10, y, z, ask what is the median of these 3 numbers?
1). someting trnaslates into y + z = 20 (y-13 = 7 - z or something like this).
2). y = 5
Answer should be C.

one JJ question: 3 people, each completes a task with x, y, x respectively, ask if work together, what's the time?
1/(1/x + 1/y + 1/z) = xyz/(xy + yz + xz)

#154: asnwer A

#167: the answer is the one that the the only difference in the equation is the number changed:
ax^2 + bx + c1 and ax^2 + bx + c2 obviously have no intersect, assuming c1 <> c2. In the question, c1 is 1, and the c2 is 2 (or 3), anyway, that's the point here.

question: some econmic indicator is proportional to sqaure of unimployment rate, ask: if the unimployement rate increases by 10%, how much that indicator will increase? 1.1^2 - 1 = 0.21 = 21%

question: d is the maximun divisor for both x and y, and 1 < d < x, 1 < d < y, ask which one of the choices also has the d as the maximim divisor:
1). x and 1,
2) xy and something
3) y and y-x (or x- y something)

I chose 3) only, since in 1), 1 is not good, and in 2). xy's maximum vivisor would be d^2, not d.

question: 2 3-digit numbers m and n, let t be the sum of the middle digits of them, ask what is t?
1). last digit (unit digit) for both numbers are greater than 6
2). the number (m+n) has the 7 at the hundreds place.

Answer should be C: both conditions combined can lead to the answer of 6 (due to round up of 1 from the unit digit addition)

QuestionL similar to #205, pattern-wise, everything else is different.

#217: the numbers are diiferent.

#220 is actually my first question, it says: the costs is: f(x) = 11x + 140 where x is the number of the thing mentioned, the sale price for each piece of that thing is $20, ask the company needs to produce and sell how many in order to make at least $500?
20x - (11x + 140) >= 500 ==> 9x >= 640 ==> x >= 71.11, so the answer should be 72

小米粒的愿望 · 发表于 2008-4-17 08:23:00

谢谢楼主，你能share一下RC和CR吗？

谢谢啦

sy1103mstr · 发表于 2008-4-17 10:23:00

Sorry, the first post got overwritten when I tried to update it.

Here I will try to add those back:

AA: A magazine is sold out, and the magazine features the pictures of an excercise machine. The conclusion is the comunity fitness centers should by this kind of excercise machines.

AI: Schools should primarily focus on teaching academic skills, not the ethical or social values.

RC:
    Manafacturing company site locations (2 questions, same as JJ)
    Canadian women journalist (did not read the JJ) - article is easy, questions are easy to locate and the answers are obvious.
    Songbird (same questions as in GWD)
    80-20 loyal customer (did not read the JJ) - article is easy, questions are easy to locate and the answers are obvious.

CR:
    Whale-otter death (same as JJ) - answer is "whale predate other animals if otter not available"
    Students seating (same as JJ) - answer is the one with "more time --> more work" (or "less time --> less work")
    Plant invasion and beetle as its natural enemy and therefore for the plant control. Plant produces toxins and make the beetle ineffective. Ask for weakening? I chose the first one: with the toxin in its body, beetle continues feeding on the plants.
    Oil shortage and hard-currency: a new oil well is found but it's a different kind of oil, it can not be used (or easily used, or something like that), and it sells well outside the country. Conclusion is that it will alleviate the oil shortage problem in the country. Ask for support? answer is the one that "sell it in international markets and use the money to buy oil".

hippo3000 · 发表于 2008-4-17 10:27:00

question: 2 3-digit numbers m and n, let t be the sum of the middle digits of them, ask what is t?
1). last digit (unit digit) for both numbers are greater than 6
2). the number (m+n) has the 7 at the hundreds place.

Answer should be C: both conditions combined can lead to the answer of 6 (due to round up of 1 from the unit digit addition)

楼主确定吗，反例是 306,406, t=0; 316,406, t=1

so the answer is E?

sy1103mstr · 发表于 2008-4-17 10:37:00

Sorry, my fault. It should be the middle digit of (m+n), not the hundreds digit.

kenzopeace · 发表于 2008-4-17 11:06:00

Thanks for sharing

依然jmy · 发表于 2008-4-17 14:32:00

以下是引用hippo3000在2008-4-17 10:27:00的发言：

question: 2 3-digit numbers m and n, let t be the sum of the middle digits of them, ask what is t?
1). last digit (unit digit) for both numbers are greater than 6
2). the number (m+n) has the 7 at the hundreds place.

Answer should be C: both conditions combined can lead to the answer of 6 (due to round up of 1 from the unit digit addition)

楼主确定吗，反例是 306,406, t=0; 316,406, t=1

so the answer is E?

这个我也觉得不大理解，是选E还是lz的表述有点问题？？

北美4月16 - 710(M50V36)

北美4月16 - 710(M50V36)

所属分类: GMAT考试

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