What is POAC And please help me solve the last second question of the class I am - Chemistry - Basic Concepts in Chemistry

Question

What is POAC?? And please help me solve the last second question of
the class I am confused

Lalit Kumar Sethia · Accepted Answer

Dear student, POAC is the abbreviation used for Principle of Atom
Conservation It is very useful technique to solve the problems of
'chemical equations' quickly & accurately too,especially in
competitions it gives you an edge over others POAC can be used for
those atoms which are conserved in a chemical reaction Principle of
atom conservation based on the conservation ofmass of atom or mole
of atom, or number of atom Balanced equations are not needed for
solvingstoichiometry problem by POAC method Regards

What is POAC?? And please help me solve the last second question of the class. I am confused