Multiple choice

The average of 11 results is 60. If the average of first six results is 58 and that of the last six is 63. Find the sixth result.

  1. $66$
  2. $70$
  3. $78$
  4. $85$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The sum of 11 results is 11 * 60 = 660. The sum of the first six is 6 * 58 = 348, and the sum of the last six is 6 * 63 = 378. The sixth result is (348 + 378) - 660 = 726 - 660 = 66.

AI explanation

The sum of all 11 results is 11 times 60, which is 660. The sum of the first six results is 6 times 58, which equals 348, and the sum of the last six results is 6 times 63, which equals 378. Adding these two sums gives 726, which counts the sixth result twice. The sixth result is found by subtracting the total sum of all 11 results from this combined sum, so 726 minus 660 equals 66.

Keep practicing — related questions