For the following taxpayers, determine if they are required to file a tax return in 2018 Problem 8-80 Part-a a. Ricko, single taxpayer, with gross income of $15,800. Required Not required For the following taxpayers, determine if they are required to file a tax return in 2018 Problem 8-80 Part-a a. Ricko, single taxpayer, with gross income of $15,800. Required Not required