The mean weight of a class of 34 students is $46.5\text{ kg}$. If the weight of the teacher is included, the mean rises by $500\text{ g}$. Find the weight of the teacher.
Step-by-Step Solution
Key Concept: Original total weight $= 34 \times 46.5 = 1581\text{ kg}$.<br>New mean $= 47.0\text{ kg}$. Total students + teacher $= 35$.<br>New total weight $= 35 \times 47.0 = 1645\text{ kg}$.<br>Teacher's weight $= 1645 - 1581 = 64\text{ kg}$.
Original total $= 34 \times 46.5 = 1581\text{ kg}$. [1.0 Mark]
New total $= 35 \times 47.0 = 1645\text{ kg}$. [1.0 Mark]
Teacher weight $= 1645 - 1581 = 64\text{ kg}$. [1.0 Mark]
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🎯 Official CBSE Marking Scheme:
Calculating original sum $= 1581\text{ kg}$: 1.0 Mark
Calculating new sum $= 1645\text{ kg}$: 1.0 Mark
Evaluating teacher's weight $= 64\text{ kg}$: 1.0 Mark
Correct Answer: