S1: The teacher enquired whether there is any problem with the question paper. S2: He asked her whether she had some pets at home.

'Any' is typically used in questions and negative statements, while 'some' is used in affirmative statements and in offers/requests where a positive answer is expected. In S1, 'enquired whether there is any problem' correctly uses 'any' in an indirect question. In S2, 'asked her whether she had some pets' is incorrect because in such a genuine yes/no enquiry, 'any pets' would be the standard usage — 'some' would be appropriate only when expecting a 'yes' answer. Hence S1 is right and S2 is wrong.