flyinghai

Isnt the semicolon in A awkward? The second sentence is not independent by itself? Any thoughts ?

How do you know n/3.3.2 is integer? n/3.3.2 could be 1/5, making 5n/18 an integer. So am still not sure if n/18 is an integer with (1)

Is n/18 integer? 1) 5n/18 is an integer 2) 3n/18 is an integer

Ye not clear at all - to me it is like asking what is the probability of 10

Ok - I know what i am missing. My answer would be correct if the guy would replace the card in the pack every time he picked one - meaning pick one and place it back, pick 2nd and place it in the pack etc.. But here the guy just randomly picks 5 cards at once !

How about this solution: 1 - (10/13)^5. What am i missing?

I agree with chix47ntu. They are not parallel lines. You know that for sure since the angles given are not in line with what they should be for the lines to be parallel. (vertical angles concept)

I think the answer should be 5.4. Can anyone confirm? He walks 240 ft at 6ft/sec until he catches up with the group [x/3 = (120+x)/6; x = 120; Hence the 240 ft] . Remaining 60ft his speed is 3ft. So, (240*6 + 60*3) / 300 = 5.4

700plus2010 - Do you have the solution for this? Is this a question from any practice test?

Nice explanation kingrulz ! thanks.

By the way the answer is: c) two

Right on clock60 !!

That is one possible way to look at it and hence is the right answer. Another way to look at it is say five members age today is 20 20 20 30 10 (make up for 20 avg). Ten yrs ago this would be 10 10 10 20 (since the young member wasn't born) The average of this is 12.5 also.

For how many integers n is 2^n = n^2 ? a)none b) one c) two d) three e) more than three I know how to back solve but is there a definite way to solve this?

Ok - i did some research and figured that the difficulty level goes up with the problem number. So the higher the problem number the more difficult the questions are - in GMAT OG 12th Ed as well as the OG Verbal and OG Quant books. It's amazing how much work these folks have done here: GMAT Official Guide 12th Edition: Problem Solving thanks everyone!