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? explain answer​

Answer 1

Answer:

Total student age= 30×12=360

Another student age =6×15=90

Step-by-step explanation:

total age = 360 +90=450

total student= 30+6=36

average age=450/36=12.5 answer

Answer 2

Step-by-step explanation:

average = 12 years

average of extra students =15

extra students average = 15-12 = 3 years more than average of present students

increase in years = 3×6 =18

increase in overall average years of total students =

18/(30+6) = 18/36 = 1/2 = 0.5

average of all students = 12+0.5 = 12.5

alternatively:

30×12 +(6×15) 360+90 450

___________ = _______ = ____ = 12.5

(30+6) 36 36