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Which of the following is closest to the value of

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papa.baffour
 Post subject: Which of the following is closest to the value of
 Post Posted: Tue Sep 01, 2009 12:58 am 
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Course Students


Posts: 7
Does anyone know of a quick and effective way to solve/estimate this? Came across it in prep test 1.

Which of the following is closest to the value of 999/(100+1/999)?

a. 10
b. 1
c. 0.1
d. 0.01
e. 0.001

Thanks.
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sunny.jain
 Post subject: Re: Which of the following is closest to the value of
 Post Posted: Tue Sep 01, 2009 1:02 am 
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Students


Posts: 111
999/(100+1/999) ==> 999/100

9.99 ~ 10

Just ignore the value of 1/999 == 1/1000 == 0.001 == 10 + 0.001 == 10
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papa.baffour
 Post subject: Re: Which of the following is closest to the value of
 Post Posted: Thu Sep 03, 2009 5:43 am 
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Course Students


Posts: 7
Thanks a lot Sunny! That was helpful.
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jigar24
 Post subject: Re: Which of the following is closest to the value of
 Post Posted: Fri Sep 04, 2009 1:17 am 
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Students


Posts: 57
Hey,

just to elaborate on what sunny said - remember the trick for any no. divided by 9, 99, 999 and so on..

e.g. 54/99 = 0.545454545454....

7/9 = 0.7777777777....

Similarly, here,

we can first simplify 1/999 => 0.001001001...

Thus, we are left with,

999/100.001001..

we can round it up to 999/100

Clearly answer option is (A) is the best choice
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papa.baffour
 Post subject: Re: Which of the following is closest to the value of
 Post Posted: Fri Sep 04, 2009 5:27 am 
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Course Students


Posts: 7
Thanks Jigar! That's a really helpful tip.
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RonPurewal
 Post subject: Re: Which of the following is closest to the value of
 Post Posted: Fri Sep 25, 2009 11:39 pm 
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ManhattanGMAT Staff


Posts: 7146
sunny.jain wrote:
999/(100+1/999) ==> 999/100

9.99 ~ 10

Just ignore the value of 1/999 == 1/1000 == 0.001 == 10 + 0.001 == 10


yes.

1/999 is ridiculously small compared to 100. (100 is almost 100,000 times as big!)

furthermore, the answer choices to this problem are incredibly far apart (each one is TEN TIMES as big as the next one).

either one of these alone - but especially both of them together - is a compeling reason to estimate.
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