Question

The average weight of a class of 35 students is 47$\frac{1}{2}$ kg. If the weight of the teacher is included, the average rises by $\frac{1}{2}$ kg. Then the weight of the teacher is

• A. 63$\frac{1}{2}$
• B. 58$\frac{1}{2}$
• C. 65$\frac{1}{2}$
• D. 60$\frac{1}{2}$

Answer 1

Answer: (C)

65$\frac{1}{2}$

Average weight of 35 students = $47\frac{1}{2}=\frac{95}{2}$ kg.
Sum of weights of 35 students = $\frac{95}{2}\times 35=\frac{3325}{2}$ kg.
Average weight of teacher & 35 students 48 Sum of weight of 35 students and teacher = 1728
Weight of teacher = 1728 - $\frac{3325}{2}=65\frac{1}{2}$ kg.