## Sunday, October 4, 2009

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- Ariel Goldberg
- My name is Ariel Goldberg and I have been a GMAT tutor for eight years. I have taken the GMAT more than twenty times and scored into the 99th percentile; I like to share my GMAT knowledge with everybody. One of the things I like is to write GMAT quant questions that do reflect the changes in the test. The questions sold by some prep services are outdated in that they reflect the GMAT of three or four years ago, before Pearson took over. So that is where I come in, I provide people with good, real-looking GMAT questions.

OA E

ReplyDeleteresultant outcome of this eqn is

23times 9 followed by 440 i.e.

9999999....(23times)...440

sum of this number is 8 not divisible by 3..Hence OA E

11,8,5,4 divisible

Yep, good job Bhushan, answer is E. And also, if you are in a hurry you can quickly eliminate B, C, and D, because the number is gonna end in a zero, so it will be divisible by 5 and will have the two 2s and three 2s to make it divisible by 8.

ReplyDeletei agreed with the explanation above

ReplyDeletecan u tell me why answer is not 11??

This comment has been removed by the author.

ReplyDeleteThis comment has been removed by the author.

ReplyDeleteThe logic is cryptic:

ReplyDelete1000-560=440 div

10000-560=9440 not div

10^5-560=99440 div

10^6-560=999440 not div

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10^(2k+1)-560 is div by 11

10^(2*12+1) - 560=9...(22*times)440 is div by 11

Basic relation is #of 9's=#10's-3

because 10000-560 gives the 1st 9

What you need to remember is you need an even number of 9's in this case for div by 11.

Man - I had to correct my post twice !

divisibility by 11= difference between odd and even placed numbers .

ReplyDeleteHere 10^25-560= 9999.(22times)440.

All 9's will cancel with each other as even number of terms. Then we have 440. So, 4+0-4 =0

Hence divisible by 11