Problem:
The average age of the people in Room is . The average age of the people in Room is . If the two groups are combined, what is the average age of all the people?
Answer Choices:
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Solution:
The sum of the ages of the people in Room is . The sum of the ages of the people in Room is . The sum of the ages of the people in the combined group is , so the average age of all the people is .
Answer: .
The problems on this page are the property of the MAA's American Mathematics Competitions