if in the question there are three years as P₀,P₁ and again P ₁ so then do we need to find the index no. of the two years separately????? taking P₀ as the base year ( as mentioned in the question)???????

Dear Student,

First of all if there are three years in the question, then they will be named as $P_0, P_1 \mathrm{and} P_2.$
In the question, it will be specifically mentioned whether to find index number for single year or both the years. 

All the best for your exams!!