Question

The average weight of a class of 20 students is 40 kg. When a teacher replaces a student, the average weight increase by 2 kg. What is the weight of the teacher

Answer 1

Answer:80kg is teacher's weight

Step-by-step explanation:1 student weight = 40kg

20 students weight = 20*40 =800

So,average is 800/20 = 40kg

Like that,19 students weight is 760kg

Let X be one teacher weight

So,avg of 19 students + 1 teacher is 760 + X / 20

(760+X )/20 =42 (given as avg weight of 19 stu. 1 teach.)

X = 42*20-760

X = 80