M is employed as a marketing analyst and required by his employment contract to maintain a home office. His office occupied 10% of the total space in his home. He works 3 days a week in his home office and travels the remaining 2 working days. He incurs the following expenses: New desk $800, telephone (10% of total) $200; Internet (10% of total) $420; Utilities (10% of total) $500; House Insurance (10% of total) $150; Mortgage interest (10% of total) $900; Property taxes (10% of total) $740; Maintenance (10% of total) $100. What is the maximum deduction from employment income for tax purposes available to M in the current year?

Please do explain, and please I want a correct answer.