Multiple choice

The average weight of 15 students in a class increases by 1.5 kg when one of the students weighing 40 kg is replaced by a new student. What is the weight (in kg.) of the new student?

  1. $64.5$
  2. $56$
  3. $60.5$
  4. $62.5$
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

When the average of 15 students increases by 1.5 kg, the total weight increases by 15 × 1.5 = 22.5 kg. The new student must weigh 22.5 kg more than the student they replaced (40 kg). Therefore, new student's weight = 40 + 22.5 = 62.5 kg. This is a standard average replacement problem where the change in total equals the number of items multiplied by the change in average.

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