Practice Test Discussion

Q)

The average of marks obtained in 120 students was 35. If average of passed candidates was 39 and that of failed candidates is 15, the numbers of candidates who passed the examinations is?

 [General Insurance Corporation (AAO), 2000]

    • Explanation

    Given,

    Total marks obtained by 120 students = 120×35

     = 4200

    Let the number of passed candidates = x

    Then, total marks obtained by passed candidates = x×39

    And, total marks obtained by failed candidates =(120-x)×15

    Again, 39x+(120-x)×15=4200

    ⇒ 39x+1800-15x=4200

    ⇒ 24x=2400

    ∴ x=240024=100

    Hence, Option A is correct.

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