The average weight of 45 students in a school is 55 kg. If the weight of the teacher is included, the average weight rises by 300 grams. Find the weight of the teacher.
Show answer & explanation
Correct answer: B
Explanation
The correct answer is Option 2 i.e. 68.8 kg.
We know that,
Average = Sum of observations/Number of observations
The average weight of 45 students of a school is 55 kg
The weight = 55 × 45 = 2475 kg
If the weight of the teacher is included,
The average weight becomes = 55 + 0.3 = 55.3 kg.
The net weight of 46 persons = 55.3 × 46 = 2543.8 kg
Hence,
The weight of the teacher = 2543.8 - 2475 = 68.8 kg