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What is the greatest positive integer n such that 2^n is a factor of 12^n? I'm totally confused...

Helping out with the effort. I think this thread has more than 4200 posts by now.

Every box has 27 * 2 = 54 chocolate creme candies. The sequence of flavors is vanilla, o, c, vanilla, r, l, p, c, l. This sequence repeats itself throughout the box. The sequence has 9 candies and repeats itself 54 / 9 = 6 times. Vanilla appears in each sequence twice. 6 * 2 = 12 is the total number of vanilla flavored candies in every box. 12 * 200 boxes = 2400 vanilla flavored candies total.

Thanks! It didn't occur to me to look at only the units digit, was going nuts trying to find a consistent pattern looking at the tens and units digits together!

Does anyone know the fastest way to solve this problem? I can do the math on a calculator but there's got to be a faster way... Question: Which is bigger? Column A The value of the units' digit in 6^47. Column B The value of the units' digit in 5^77.

The formula doesn't really matter, you just have to remember to calculate two points like this: point A is (3, 2), point B is (-4, 6). The slope of the line that intersects these two point is (6 - 2) / (-4 - 3) = 4 / (-7) = - 4/7 Subtract the first y value from the 2nd y value and subtract the first x value from the 2nd x value.

(from the newest ETS GRE prep book) A reading list for a class consists of 10 books, of which 4 are biographies and the rest are novels. Each student is required to read 4 books from the list, and at least 2 must be biographies. How many selections of 4 books satisfy the requirements? I broke down the problem like this: the first 2 of the 4 books has to be biographies and order doesn't matter, so I treated it as a combination problem C (4, 2) = 6. And then the remaining 2 books could be anything, so I treated it as another combination problem with n = 8 (because two biographies are no longer available). So, C (8, 2) = 28. Then I multiplied (6)(28) = 168 possibilities. But according to ETS this is incorrect. Does anyone know how to figure out this problem? Thank you in advance!

Of the positive integers that are multiples of 30 and are less than or equal to 360, what fraction are multiples of 12?

Apologies for not having a photo, I don't have a scanner handy, but I think the question is pretty self-explanatory. What would be the fastest way to find the answer? A rectangular label is attached to a right circular cylinder with radius r. The label, which encircles the cylinder without overlap, has width w and an area equal to the area of the base of the cylinder. Which is bigger w or r?

Yes, I'm using it. I don't know but on the recent GRE test I took (March 5, 2012) I found the difficult questions to be more difficult than the hard ones from the Big Book.

I suggest trying to get your hands on some real GRE tests and practicing on those. Nothing beats the real thing. If you're aiming for a high score, like Q800, you'll need to practice on difficult questions. I've heard that Barron's is a good book for tougher questions.

I noticed something interesting about the new GRE test and just wanted to find out of others have noticed this too. I've been practicing for the last 6 months using the GRE Big Book. My average score has been about 750 for the quant section, but on a recent actual GRE exam I only scored a 154 (~ 690) on the quant section. I'm not sure why this is happening but it seems to me the old GRE test was more about speed and accuracy, but the toughest questions weren't all that difficult. However, in the new GRE the hard questions seem to be a lot more difficult. Is it just my imagination or has anyone else experienced this? On a recent test I was asked to compare the volume of a sphere and a cylinder but no formulas were provided, so only those who had memorized the volume of a sphere would get the question right. This seems considerable harder than questions from the Big Book (I don't recall seeing any questions like this). There were 3 quant sections on my exam, so it could have just been the experimental section. But if it wasn't, the requirements for scoring high on the test seem to be a lot more demanding now.

I played around with some small numbers and came up with this: Beginning: Abby - 11 chips, Brian - 11 chips End: Abby - 13 chips, Brian - 9 chips They played a total of 2 games and Abby won both. Does this sound right?

The question above I can't seem to figure out. I have another question below, which I did figure out but I don't know if it's the correct answer. Here is the question: Abby and Brian play a betting game. In this game there are no ties. They both start with the same number of chips. Whenever one of them loses they have to a give a chip to the other person. By the end of the game Abby has won 2 games and Brian has 9 chips. How many games did they play? (look at the next post for my answer)

Thanks for the video! Going to look at it more closely later.

I can't figure out this question: There are 30 marbles in a bag. 15 are black, 9 are blue, and 6 are red. A marble is randomly drawn from the bag and placed back into the bag again. This is done twice. How much greater is the probability of drawing 2 black marbles on both attempts than the probability of drawing 2 blue marbles?

Thanks for the feedback! Are there any faster ways to calculate question # 2? I did get this answer but took me a good 4 minutes to calculate.

Got it, thanks! I can't remember any math past the first year of high school :) so drawing the 45:45:90 triangle definitely helped. And since 45:45:90 has a ratio of 1:1:root 2, one of the sides (which is also the shortest distance between the lines) would have a length of 1 / root 2. Ok, I'm just repeating this to myself so it sticks. My GRE test is tomorrow (shudder).

(from GRE Big Book) I can't figure out these two questions. Would love to know the answer and any shortcuts to finding the answer faster! Questions 1: In the rectangular coordinate system below (vertical is y axis, horizontal is x), if the equation of the left line is y = x and the left line is parallel to the right line, what is the shortest distance between the left and right lines lines? Left line goes through (0, 0) and right line goes through (1, 0). [ATTACH=CONFIG]6444[/ATTACH] A. square root of 2 B. 1 C. (square root of 2) / 2 D. 1 / 2 E. 1 / 4 Question 2 Given the equation below, which value is larger? [ (2x + 1) / 4 ] - [ (x - 1) / 8 ] = [ (x - 1) / 4 ] - [ (2x + 1) / 8 ] A. 2x + 1 B. x - 1

A quant comp question from p. 544 of the GRE Big Book: [picture of a cube] The volume of the cube is x cubic meters and the surface area is x square meters. Column A The length of an edge Column B 6 meters (I have no idea how to do this problem. Please give an explanation along with the answer if you know it, thanks!)

Yes, a 161 in quant is like a 770 in the old scale. A Q770 can get you into top 20 engineering programs in the U.S., but maybe not the top 10. I'm trying to get into a top 30 program for computer science so I'd love to have your math score :blue: Keep trying if you're aiming for MIT!

I usually do worse on the Quantitative portion, so got really lucky this time with a verbal experimental section (whew). Does anyone know what the new scores correspond to? This website (http://d480ut78k5icv.cloudfront.net/wp-content/uploads/2011/11/New-GRE-Score-Converter-Quantitative.png?9d7bd4) says that Q 154 is about a 690 on the old scale and V 161 is about a 620 on the old scale. Can anyone confirm this?

I'm applying to some masters programs in computer science (NYU, Columbia, and Polytech University). I'm planning on taking the GRE test every 60 days until my math score is high enough to get me into these schools. I was told NYU requires Q720, Columbia is Q750 and I'm not sure about Polytech. Does anyone know how graduate schools feel about multiple GRE scores? Are they willing to just look at your highest score? I had taken a GRE test in July of this year but did very badly. I'm planning to take it again at the end of this month (December) then every 60 days after that. Does anyone know if graduate departments look badly on your application if you submit multiple GRE scores?

Yes, I'm taking it on Dec. 31st. I'm studying from Barrons book and thinking about buying the Nova GRE prep online course. I'm just going to keep taking the GRE every 60 days until my math score is high enough for the graduate programs I'm applying to...

Thanks for the replies. I'm going to work on learning the tricks and short cuts. I went over all the tests I've taken over the past months and realized I'm screwing up because of the pressure of a timed test! When you've only got 30 minutes to do all the questions it's easy to panic and make careless mistakes! I'm sure other people have this problem too. If the GRE math were untimed I know lots more people would be scoring 800 on the test. Un-timed I have done Q800. So...my new question is: How do you do math problems faster?