Compute Ofonime's tax liability for the relevant year of assessment, considering his salary, family, company benefits, and retirement payments.

Here is the computation of Ofonime's tax liability for the relevant year of assessment, which is assumed to be 2010, the year of his retirement.

Assumptions:

• The official car benefit is calculated as $5\%$ of its market value.
• Gratuity and lump sum for loss of office are exempt from income tax.
• Dependent relative relief is limited to $\text{N}2,000$ per dependent, for a maximum of two dependents, as per the Personal Income Tax Act (PITA) 2004.
• Consolidated Relief Allowance (CRA) for 2010 is calculated as the higher of $\text{N}5,000$ or $1\%$ of gross income, plus $20\%$ of gross income.

Step 1: Calculate Gross Emoluments This includes all taxable income and benefits in kind.

• Salary: $\text{N}500,000$
• Accommodation: $\text{N}180,000$
• Official Car Benefit: $5\%$ of $\text{N}2,000,000 = N100,000$ $Gross Emoluments = N500,000 + N180,000 + N100,000 = N780,000$

Step 2: Deduct Allowable Expenses/Contributions