Google made a list of the top 10 tax questions that people queried since Jan. 1, 2015, and the states where people queried the most tax-related questions. The type of answers people search for online are puzzling. The No. 1 question: What is income tax? The No. 10 question: Who has to file income tax? The questions between 1 and 10 are just as worrisome. Maine, Ohio, Arkansas, Delaware, and Louisiana are the top five states.