Question

The average age of students of a class increases by 2 when a student of 49 year old joins the
class. If the original average was 31. then find number of students at present in the class.​

Answer 1

Answer:

Let the number of student present in the class will be-X

then the sum of student present in the class will be-31 X

after joining the 49 years student the average will be-31+2=33

so,                 31 X + 49

                =>    ---------------  =33

                          X+1

                  => 31 X+49=33(X+1)

                 =>  31 X+49=33 X +33

                 =>  49-33=33 X-31 X

                  =>  16=2 X

                  =>   X=8 ANS

Step-by-step explanation: