can somebody provide a solution to this problem?

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by Brent@GMATPrepNow » Sun Aug 04, 2013 6:18 am
sethiharshal wrote:The sum of n consecutive positive integers is 45. What is the value of n?

(1) n is even

(2) n < 9
Target question: What is the value of n?

Given: The sum of n consecutive positive integers is 45.
Let's see what this given information tells us.
Some possible scenarios:
- the numbers are 1,2,3,4,5,6,7,8,9
- the numbers are 5,6,7,8,9,10
- the numbers are 7,8,9,10,11
- the numbers are 14,15,16
- the numbers are 21,22
At this point, we should see that the answer is E.
To see why, let's go straight to . . .

Statements 1 and 2 combined
There are two sets of consecutive numbers that meet the two given conditions:
Case a: the numbers are {5,6,7,8,9,10} in which case n = 6
Case b: the numbers are {22,23} in which case n = 2
Since we cannot answer the target question with certainty, the combined statements are NOT SUFFICIENT

Answer = E

Cheers,
Brent
Brent Hanneson - Creator of GMATPrepNow.com
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by sethiharshal » Sun Aug 04, 2013 11:25 am
oh okay. just got the mistake i was doing thru your explanation.
thank you, sir!