Multiple choice

The average of 12 numbers is 16.4, the average of 13 numbers is 12.4 and the average of remaining five numbers is 20.8. The average of 30 numbers will be ______.

  1. 16.4

  2. 15.4

  3. 14.4

  4. 17.2
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B Correct answer
Explanation

The total sum of the numbers is (12 * 16.4) + (13 * 12.4) + (5 * 20.8) = 196.8 + 161.2 + 104 = 462. The average of the 30 numbers is 462 / 30 = 15.4.

AI explanation

The sum of the first 12 numbers is 12 multiplied by 16.4, which is 196.8. The sum of the other 13 numbers is 13 multiplied by 12.4, which is 161.2, and the sum of the remaining 5 numbers is 5 multiplied by 20.8, which is 104. The total sum of all 30 numbers is 196.8 plus 161.2 plus 104, resulting in 462. The overall average is 462 divided by 30, which gives 15.4.

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