Mr. Arnold Navales is a Certified Public Accountant. He is a part-time University professor and engages in trucking industry. He has a two (2) qualified dependent children. His wife is also engaged in catering services, but he opted to file their returns separately and claimed (2) dependent children for the additional exemptions. The following data are given for 2020: Gross Income from business P680,000 Operating Expense 580,000 Salary as part time professor 42,000 (net of Withholding Tax P6,000) Required: (5 points each) 1. Determine the Gross Income. 2. How much amount can be deducted from 2019 gross income? 3. How much tax is his taxable income? 4. How much is tax due? 5. How much amount taxable by BIR