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Re: Sets S and T contain an equal number of elements, all of which are pos [#permalink]
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Sets S and T contain an equal number of elements, all of which are positive integers. x is the median of S and y is the average (arithmetic mean) of T. Is x > y ?

So this question is asking if the median of set S is greater than the median of set T. I know they each have the same number of numbers, and that each number is a POSITIVE INTEGER. That's useful to notice (always important to consider whether negatives/fractions are in play), but there's not much more given to investigate, here.

(1) The sum of S is greater than the sum of T

Okay. That tells me the average of S is larger (since they have the same # of numbers), but that doesn't tell me about the median. Averages and medians don't *have* to have a lot in common, really.

The sum of S could be large because the biggest number in S is 10 gazillion, but its median might be rather small (or large, who knows?) relative to the median of T. I'd eliminate A and D.


(2) S consists of consecutive even numbers and T consists of consecutive odd numbers

So this tells me that in each set the Median = Average, since that's what consecutively spaced sets cause. But it doesn't tell me where these sets are relatively to each other. Eliminate B.




Now that I take the two together, the answer becomes clear. Since in each set, the average = median (per statement 2), and since the average of S > Average of T (per statement 1), I know the Median of S > Median of T.

Answer is C.

PRIMARY TAKEAWAYS:
--in a consecutively spaced set, the median = average
--When dealing with a set, the SUM and the AVERAGE interplay (so long as # is fixed). Increase a sum? Increase the average (and vice versa). It can be helpful to remember--if information about the individual numbers isn't given--that you can increase a sum by increasing each number a 'little,' or by increasing one number a 'lot.'
--Median and Average have little in common conceptually. How 'close' they are intends entirely on the set.
--It can be efficient and helpful to go 'extremes' when testing cases.

GMAT Club Bot
Re: Sets S and T contain an equal number of elements, all of which are pos [#permalink]
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