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If set s={7,y,12,8,,x,9} is x+y less than 18? 1.range of set
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24 Mar 2011, 00:50
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65% (01:03) correct 35% (00:49) wrong based on 110 sessions
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If set s={7,y,12,8,,x,9} is x+y less than 18? 1.range of set s is less than 9 2.average of x and y is less than average of set s. == Message from the GMAT Club Team == THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION. This discussion does not meet community quality standards. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.
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Re: explain the concept !
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24 Mar 2011, 02:19
If range is less than 9, then the difference between the largest and teh smallest members of the set should be ,9 The difference of all the given numbers < 9 So even if we were to assume that the difference between x and y is less than 18 then let us try to find values of x and y So x = 7 + 10 = 17 y can be the same as well = 7 + 10 = 17 So x + y can be > 18, Again, x+y can be any other numbers as 1 and 2, and the range is still < 9. so (1) is not sufficient. From (2) (x+y)/2 < (7 + y + 12 + 8 + x + 9)/6 => 6(x+y) < 2(x+y + 36) => 4(x+y) < 2*36 => (x+y) < 18 So Answer  B
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Re: explain the concept !
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25 Mar 2011, 06:22
AnkitK wrote: If set s={7,y,12,8,,x,9} is x+y less than 18?
1.range of set s is less than 9 2.average of x and y is less than average of set s. (1) x= 5, y= 11 range (125) is less than 9 and x+y <18 but x= 5, y= 13 here range is less than 8 but x+y=18 so INSUFFICIENT. (2) (X+Y)/2<(7+y+12+8+x+9)/6 X+Y<18 SUFF. ANS B
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Re: If set s={7,y,12,8,,x,9} is x+y less than 18? 1.range of set
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14 Apr 2016, 02:20
In order to prove that option B is the right answer we are multiplying the inequality by the LCM (6) without knowing if x+y is positive or negative. Is there any reason for x+y to be assumed to be positive? == Message from the GMAT Club Team == THERE IS LIKELY A BETTER DISCUSSION OF THIS EXACT QUESTION. This discussion does not meet community quality standards. It has been retired. If you would like to discuss this question please repost it in the respective forum. Thank you! To review the GMAT Club's Forums Posting Guidelines, please follow these links: Quantitative  Verbal Please note  we may remove posts that do not follow our posting guidelines. Thank you.



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Re: If set s={7,y,12,8,,x,9} is x+y less than 18? 1.range of set
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08 Apr 2019, 15:35
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Re: If set s={7,y,12,8,,x,9} is x+y less than 18? 1.range of set
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08 Apr 2019, 15:35






