GMAT Prep Question - Please help solve!

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GMAT Prep Question - Please help solve!

by wakawaka111 » Mon Feb 22, 2010 8:45 pm
Can someone walk me through this problem?

For every integer k from 1 to 10, inclusive, the kth term of every sequence is given by (-1) ^k+1 (1/2^k). If T is the sum of the first 10 terms in the sequence, then T is

- greater than 2
- between 1 and 2
- between 1/2 and 1
- between 1/4 and 1/2
- less than 1/4

Answer: [spoiler]between 1/4 and 1/2[/spoiler][/i]
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by komal » Mon Feb 22, 2010 8:56 pm
wakawaka111 wrote:Can someone walk me through this problem?

For every integer k from 1 to 10, inclusive, the kth term of every sequence is given by (-1) ^k+1 (1/2^k). If T is the sum of the first 10 terms in the sequence, then T is

- greater than 2
- between 1 and 2
- between 1/2 and 1
- between 1/4 and 1/2
- less than 1/4

Answer: [spoiler]between 1/4 and 1/2[/spoiler][/i]
Hi wakawaka111,

Welcome to the BTG Community. This question has already been discussed before. Here's the link :

https://www.beatthegmat.com/sequence-exp ... 31657.html

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by wakawaka111 » Mon Feb 22, 2010 9:01 pm
Awesome -- thanks!