Multiple choice

The average age of 6 members of a family is 20 years. If the age of the servant is included, then the average age increases by 25%. What is the age (in years) of the servant?

  1. 30

  2. 35

  3. 50

  4. 55

  5. None of these
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D Correct answer
Explanation

Initial sum of ages = 6 * 20 = 120. New average = 20 * 1.25 = 25. New sum of ages = 7 * 25 = 175. Servant's age = 175 - 120 = 55.

AI explanation

The initial total age of the 6 family members is 6 * 20 = 120 years. When the servant is included, the average age increases by 25%, making the new average 20 * 1.25 = 25 years. The total age for 7 people at this new average is 7 * 25 = 175 years. The servant's age is the difference between the new total and the old total, which is 175 - 120 = 55 years.

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