Averages · Question 26 · Medium
The average of 9 numbers is 22. The average of the first five is 20 and the average of the last five is 25. What is the fifth number?
- 25
- 23
- 27
- 29
Answer and explanation
Answer: C. 27
Explanation: The fifth number is counted in both groups: 5 × 20 + 5 × 25 − 9 × 22 = 100 + 125 − 198 = 27.
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