Multiple choice

Three years ago the average of A, B, C was 27 years and that of B and C, 5 years ago was 20 years A's present age is

  1. 40 years

  2. 48 years

  3. 30 years

  4. 35 years
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Three years ago, the sum of ages of A, B, and C was 27 * 3 = 81. Their present sum is 81 + 3*3 = 90. Five years ago, the sum of B and C was 20 * 2 = 40. Their present sum is 40 + 5*2 = 50. A's present age is 90 - 50 = 40.

AI explanation

Three years ago, the average age of A, B, and C was 27 years, making their total age 3 times 27, or 81 years. Their present total age is therefore 81 plus 3 times 3, which equals 90 years. Five years ago, the total age of B and C was 2 times 20, or 40 years, making their present combined age 40 plus 2 times 5, which is 50 years. A's present age is the total present age of all three minus the combined present age of B and C: 90 minus 50 equals 40 years.

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