The Average marks in statistics of 10 students were 68. A new student with 72 marks where as 2 existing students left the college. If the marks of these students were 40 39, find the Average marks?
average=total marks/total students
now adding the marks of new student and subtracting the marks of students who left we will get new total marks i.e,
and adding new student to total students and subtracting 2 students who left from them we get new no. of students
now, new average=new total marks/new no. of students