In the question, two statements are given followed by three or four conclusions numbered. I, II, III and IV. You have to take the given statements to be true even if they seem to be at variance from the commonly known facts and then decide which of the given conclusions logically follows from the given statements disregarding commonly known facts.
Statements : All shares are debentures. No debenture is an equity
Conclusions: I. No equity is a share. II. Some debentures are shares. III. No share is an equity