Multiple choice

Passage

Direction: Read the following question carefully and choose the right answer.

Present average of age of A and B is 6x - 15 years. Present average age of A, B and C is 4x + 6 years. If present age of B is 25% less than the present age of C and 20% more than the present age of A, then find the present age of A.

  1. 30 years

  2. 33 years

  3. 36 years

  4. 39 years

  5. Can't be determined
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

A+B = 2(6x-15) = 12x-30. A+B+C = 3(4x+6) = 12x+18. C = (12x+18) - (12x-30) = 48. B = 0.75C = 36. B = 1.2A => 36 = 1.2A => A = 30.

AI explanation

Since B is 20 percent more than A, B equals 1.2 times A. Since B is 25 percent less than C, B equals 0.75 times C, meaning C is 4/3 times B, which is 1.6 times A. The total age of A and B is A + 1.2A = 2.2A, and their average is 1.1A, which is given as 6x - 15. The total age of A, B, and C is A + 1.2A + 1.6A = 3.8A, and their average is 3.8A divided by 3, which is 4x + 6. Solving 1.1A = 6x - 15 and 3.8A / 3 = 4x + 6 gives A = 30.

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