the balanced equation for the above reaction is as follows;
P₄O₁₀ + 12KOH ---> 4K₃PO₄ + 6H₂O
stoichiometry of P₄O₁₀ to KOH is 1:12
1 mol of P₄O₁₀ reacts with 12 mol of KOH
therefore 3 mol of P₄O₁₀ reacts with - 12 x 3 mol of KOH
the number of KOH moles required to react with P₄O₁₀ - 36 mol of KOH
answer is 4. 36 mol