In the Book it is given that when AP=MP , AP is at its maximum.
However in this numerical this does not happen i.e. At the maximum value of AP it is NOT equal to MP (> MP) and when it becomes equal to MP (between the 2nd and 3rd unit) it is not at its maximum value.
What is the reason behind this Contradiction???
At 3rd unit of labor, MP is maximum, i.e. 40, after that MP falls and at 4th unit AP=MP=30, and at this point AP is maximum too.
and in syllabus its also given that after MP attains maximum point, it starts falling while AP rises, it rises and attain maxmium point and at that level AP=MP.