gmat prep

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gmat prep

by navalpike » Sat Aug 15, 2009 11:12 am
240, 120, 60, 30, ……

In the sequence above, each term after the first is ½ of the preceding term. What is the least term of the sequence that is greater than 1?

32/15
16/15
15/8
15/4
15/2

Kindly explain your reasoning. I am looking for multiple ways to solve this problem.

Thanks,

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Re: gmat prep

by Morgoth » Sat Aug 15, 2009 11:30 am
next term = 30/2= 15

next term = 15/2

next term = 15/4

next term = 15/8

next term = 15/16, at this point you should stop, we need a value greater than 1, clearly 15/16 cannot be greater than 1

hence answer is 15/8.

Hope this helps.

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by niraj_a » Sat Aug 15, 2009 2:46 pm
i solved somewhat like morgoth but i confirmed if B is good to go or not via long division since i was way less than 2 mins into the problem.

it paid off - B is smaller than C.