There are 100 students in a Number of boys is 10 more than the number of girls

There are 100 students in a Number of boys is 10 more than the number of girls. The average weight of boys is 50 kg and average weight of the whole class is 45.5 kg. The average weight of girls is (in kg)

  1. 40
  2. 45
  3. 50
  4. 52
Anurag Mishra Professor Asked on 19th April 2016 in Maths.
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  • 1 Answer(s)

    Answer: (1) 40

    Solution:-
    The total number of students = 100
    The number of boys is 10 more than the number of girls.
    Then, the number of boys and girls = 55 and 45

    The average weight of boys = 50 kg.
    Then, the total weight of 55 boys = 55 x 50
    = 2750 kg

    The average weight of whole class  = 45.5 kg
    Then, total weight of whole class = 45.5 x 100
    = 4550 kg

    So, total weight of 45 girls = 4550 – 2750
    = 1800 kg
    Then, the number of girls = 1800/45
    = 40

    Hence, the correct answer is option (1) 40.

    Anurag Mishra Professor Answered on 20th April 2016.
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