knewton DS

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knewton DS

by bblast » Thu Aug 04, 2011 8:44 am
What is the value of the least integer in a set of k consecutive even integers, if the average (arithmetic mean) of the k consecutive even integers is equal to 17?

The range of the k integers is 18.
The greatest of the integers is 26.



I wanna dig into stat - 1.
range Of consecutive even or odds is always = 2(n-1)

How can I write the series in terms of n,n+2,n+4,...n+k/2 or something ?.

so that i get an equation solvable for stat 1 ?
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by Frankenstein » Thu Aug 04, 2011 8:53 am
Hi,
Average is 17. (16+18)/2
From(1):
<-- 16,18, -->
From your formula, you know that n = 10
So, add 4 numbers to right of 18 and 4 to the left of 16
So, least number number will be 16 - 4(2) = 8.
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by gmatboost » Thu Aug 04, 2011 9:55 am
Or, even simpler:

Average is 17. Range is 18.
Since 17 is right in the middle, the biggest number is 9 above 17 (26) and the smallest is 9 below 17 (8).
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