Difficulty: Easy
Correct Answer: 8
Explanation:
Introduction:
This is a sum-partition average problem. Converting averages to totals lets you subtract the known subset and then average what remains. It is a standard technique for decomposing composite averages.
Given Data / Assumptions:
Concept / Approach:
The remaining two have total = overall total − subset total. Divide by 2 to get their average. This avoids hunting individual values and relies only on aggregate information.
Step-by-Step Solution:
Verification / Alternative check:
If you construct a concrete set matching these sums, the two leftover values will always average to 8, regardless of their individual spread, since the aggregate constraints are fixed.
Why Other Options Are Wrong:
12, 6, 10, and 14 conflict with the fixed totals (112 overall and 96 for the six). Only 8 divides the remainder 16 evenly for two numbers.
Common Pitfalls:
Averaging 14 and 16 directly (which would be meaningless here) or dividing the difference of averages by 2 without using totals.
Final Answer:
8
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