Let us consider the situation where Mustafa has scored average 60 with 75 marks for math.
So total marks for four subjects `= 60xx4 = 240`
We know he got 75 for math.
So marks of other 3 subjects `= 240-75 = 165`
so even he scored 57 marks he has 165 for the other 3 subjects. So the actual mark of Mustafa is `(165+57) = 222`
So total mark of Mustafa is 222 marks.