11. The correct answer is (D). The question describes an arithmetic sequence—an evenly
spaced, finite sequence of numbers. In any arithmetic sequence, the average of all terms
is the same as the median. The average is also equal to half the sum of the first and last
number in the sequence. Thus, either statement (1) or (2) alone suffices to answer the
question. For example, the sequence might include four integers {33, 35, 37, 39} or it
might include 6 integers {31, 33, 35, 37, 39, 41}. As you can see, regardless of the
number of terms, the average and median are each the same as half the sum of the least
and greatest terms.
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