Question

the average weight of 10 students in a class of 20 is 35 kg and that of the remaining
class is 30 kg. find the average weight of all the students in the class.
a. 32.5 kg b. 30.5 kg c. 32 kg d. 33 kg​

Answer 1

Step-by-step explanation:

By using formula of combined mean.

Answer 2

Answer:

a). Average = 32.5

Step-by-step explanation:

In the question,

Total number of students = 20

The average weight of 10 students = 35 kg

The average weight of remaining 10 students = 30 kg

Therefore,

To find the average weight of the whole class we need to find out that,

$Average=\frac{(10\times 35) + (10 \times 30 )}{20} \\So,\\Average =\frac{350+300}{20}=\frac{650}{20}\\  So,\\Average = 32.5$

Because,

Average weight is given by the ratio of Total weight of all the students and the total number of students.

Therefore, Average = 32.5 kg