Question

The average age of 30 students in a class
is 12 years. If another 6 students whose
average age is 15 years are also joined
in this class, now the average age of all
students is​

Answer 1

Average age of 30 students in a class = 12 years

5 students = 10 years

Another 5 students = 14 years

remaining student= 30-5-5=20

let's assume average age of 20 student=x

Total age of all student=average age* total no of student

30∗12=5∗10+5∗14+20∗x

360=50+70+20x

360=120+20x

240=20x

x=12

Answer (C) 12 Years

Answer 2

Answer:

Average age of 30 students in a class = 12

5 students = 10 year's

Another 5 students = 14 year's

remaining students = 30-5-5=20

Let's assume average age of 20 students = ×

Total age of all students = average age * total no of students.

30* 12 = 5*10 +5*14+20×

360=50+70+20×

360=120+20×

240=20×

×=12

solution is 12