Answers

2016-02-29T13:41:44+05:30
The A.M of 30 students = 42
   sum of the 30 students
-------------------------  =  42
                30

sum of the 30 students = 42 * 30 =  1260
Now, two got zero 
so new Am of 28 students = 1260 / 28 = 45
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