Multiple choice

In a prep school, the average weight of 30 girls in a class among 50 student is 16 kg. and that of the remaining students is 15.5 kg. What is the average weight of all the students in the class?

  1. 15.2 kg.

  2. 15.8 kg.

  3. 15.4 kg.

  4. 15.6 kg.
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Total weight = (30 × 16) + (20 × 15.5) = 480 + 310 = 790 kg. Average = 790/50 = 15.8 kg. This uses weighted average: (30/50 × 16) + (20/50 × 15.5) = 9.6 + 6.2 = 15.8. Options A (15.2), C (15.4), and D (15.6) are incorrect.

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