Question

The average weight of 15 students in a group is 26 kg. When the teacher's
weight is included it becomes 30 kg. What is the weight of the teacher?
A) 78
B) 86
C) 62
D) 90​

Answer 1

Answer:

(D) 90 is the correct answer

Step-by-step explanation:

Let the weight of the teacher be x

Mean weight =  Total wt of the student/ Total number of students

26 = ∑wt of students/ 15

∑wt of students = 26x 15 = 390

now, the teachers wt is added to the total wt of the students

= 390+x

and the total number of the persons become 16. Since, 1 teacher and 15 students

∑wt of the person/ ∑no of the people = mean wt

30 = 390+x/ 16 => 390+x = 480 => x = 480-390 = 90

(D) 90