Multiple choice

Average age of 7 students of a class is 28 years. Average age of first three students is 30 years. Age of fourth students is 4 years less than the age of fifth student. Ages of last two students is same and is 5 more than the average age of first three students. What is the average age of fourth and fifth student?

  1. 18 years

  2. 36 years

  3. 16 years

  4. 20 years
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

Total age of 7 students = 7 × 28 = 196 years. First 3 students total = 3 × 30 = 90 years. Last 2 students each = 30 + 5 = 35 years, so their total = 70 years. Therefore 4th + 5th student ages = 196 - 90 - 70 = 36 years. Average of 4th and 5th = 36/2 = 18 years. The given answer A (18 years) is correct.

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