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The mean weight of 150 students in a certain class is 60 kg . The mean weight of boys in the class is 70 kg and that of girls is 55 kg . What is the number of boys in the class?

Options

  1. A50
  2. B55
  3. C60
  4. D100

Correct answer

A. 50

Step-by-step solution

Number of students = 150 By aligation, ratio =1: 2 No. of boys = 1 3 150=50

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