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NTA Abhyas JEE Main2020MathematicsStatisticsPractice

The average weight of the students in a class of 39 students is 40 k g . If the weight of the teacher is to be included, then the average rises by 1 4 k g . The weight of the teacher is

Options

  1. A40.5 k g
  2. B50 k g
  3. C41 k g
  4. D51 k g

Correct answer

B. 50 k g

Step-by-step solution

Let the weight of the teacher be w   k g , then 40 + 1 4 = 39 × 40 + w 39 + 1 ⇒ 40 × 40 + 40 × 1 4 = 39 × 40 + w ⇒ w = 50 ∴ Weight of the teacher = 50 k g

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