Multiple choice

The average age of a class of 50 students is 24 years. If the average age of 10 of them is 22 years while that of another 10 is 26 years, then what is the average age of the remaining 30 students?

  1. 23 years

  2. 25 years

  3. 24 years

  4. 28 years

  5. 22 years
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C Correct answer
Explanation

Total age = 50 * 24 = 1200. Age of 10 = 10 * 22 = 220. Age of another 10 = 10 * 26 = 260. Remaining 30 students total age = 1200 - 220 - 260 = 720. Average = 720 / 30 = 24.

AI explanation

Using the equation method for averages, the sum of the ages of all 50 students is 50 times 24, which equals 1200 years. The sum of the ages of the first 20 students is (10 times 22) plus (10 times 26), which is 480 years. The sum of the ages of the remaining 30 students is 1200 minus 480, giving 720 years. Dividing this sum by 30 gives the average age of the remaining students, which is 24 years.

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