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Discussion

  1. The average age of 30 students in a class is 12 years. The average age of a group of 5 of the students is 10 years and that of another group of 5 them is 14 years. The average age of the remaining students is ?
    1. 8 years
    2. 10 years
    3. 12 years
    4. 14 years
  1. Correct Option: C

    Let average of the remaining student be y.
    Then from questions ( 5 x 10 ) + ( 5 x 14) + 20y = 30 x 12
    ⇒ 50 + 70 + 20y = 360
    ⇒ 20y = 360 – 120
    ⇒ 20y = 240
    ⇒ y = 12.

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