Multiple choice

The average age of the first 10 persons among 12 persons is 100 years. The age of 11th and 12th person is 48 years and 22 years less than the average age of all 12 people respectively. Find the sum of the age of 11th and 12th person?

  1. 126 year

  2. Can’t be determined

  3. 137 year

  4. 116 year

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Sum of first 10 ages = 1000. Let average of all 12 be A. Then 11th age = A-48, 12th age = A-22. Total: 1000 + A-48 + A-22 = 12A, so 1000 + 2A - 70 = 12A, giving 930 = 10A, A = 93. Sum of 11th and 12th = 93-48 + 93-22 = 45 + 71 = 116.