Large Committes

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Large Committes

by smclean23 » Sun Sep 21, 2008 1:46 pm
Committee X and Committee Y, which have no common members, will combine to form Committee Z. Does Committee X have more members than Committee Y ?


(1) The average (arithmetic mean) age of the members of Committee X is 25.7 years and the average age of the members of Committee Y is 29.3 years.

(2) The average (arithmetic mean) age of the members of Committee Z will be 26.6 years.

OA is D.

How C? Couldn't X have lots more younger members like 12, 13 and Y have lots of 29 year olds? Making it impossible to tell who has more of whatever age?
Source: — Data Sufficiency |

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by k_abhi19 » Mon Sep 22, 2008 3:05 pm
The answer should be C...
The statement 1 tells you nothing about the number of members.... same is the case with statement2...
as the average age of the Community Z would be the weighted average ( the number of members in the community being the weight) of the average age of Community X and that of community Y..

and on combining the info given in statement 1 and 2 it is clear that weighted avg 26.6 is closer to that of community X (25.7) i.e community X has more members than those in Y..

Also regarding your question "How C? Couldn't X have lots more younger members like 12, 13 and Y have lots of 29 year olds? Making it impossible to tell who has more of whatever age?"...
when thinking about the possible ages of members of X... say 12,13.. etc.. do not forget that the avg age is 25.7 which is given in the Ques... HTH :)