Difficulty: Easy
Correct Answer: 27 years
Explanation:
Introduction / Context:
Average problems with replacements can often be handled by comparing total sums before and after. If the net change in total age is zero, the average remains unchanged (provided the team size is unchanged).
Given Data / Assumptions:
Concept / Approach:
Compute the total change: (23 + 28) − (24 + 27) = 51 − 51 = 0. Therefore, team total remains the same and so does the average.
Step-by-Step Solution:
1) Outgoing sum = 24 + 27 = 51.2) Incoming sum = 23 + 28 = 51.3) Net change = 0 ⇒ Average unchanged = 27 years.
Verification / Alternative check:
If the number of players stays the same, unchanged total implies unchanged average. This is independent of the actual team size.
Why Other Options Are Wrong:
Common Pitfalls:
Students sometimes attempt to average the four numbers directly; only the net change in totals relative to team size matters.
Final Answer:
27 years
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