Question

in a school,the average age of students is 6 years and the average age of 12 teachers is 40 years.if the average age of the combined group of all the teachers and the students is 7 years,then the number of students is?​

Answer 1

Step-by-step explanation:

av age of students= 6=sum of age/ no of students

sum of their age 6x...(x= no of students)

av age of 12 teachers=40= sum of age/ 12sum of age of teachers = 480

av of all= 7= sum of students age+480/ 12+x

7=6×+480/12+x

84+7x= 480+6x

x= 396 students

hope it is correct