Question 991877
The average age of class 20 boys is 12 years.
 What will the average ago of class if 5 new boys join the class whose average age is 7 year.
:
The equation when a total of 25 boys are in the class
a = {{{(20(12)+5(7))/25}}}
a = {{{(240+35)/25}}}
a = {{{275/25}}}
a = 11 yrs is the average now