What is the selling price of the article?
I. The profit on sales is 20%.
II. The profit on each unit is 25% and the cost price is Rs. 250.

if the question cannot be answered even with the help of both the statements taken together.

if the question can be answered by any one of the two statements.

if each statement alone is sufficient to answer the question, but not the other one (e.g. statement I alone is required to answer the question, but not statement II and vice versa.

if both statements I and II together are needed to answer the question.