Post Utme Abu 2023 Economics Question 36

The government of a country has decided to implement a new tax policy to reduce income inequality. The tax policy involves a progressive tax system where higher-income individuals pay a higher tax rate. However, the tax rate is not directly proportional to the income level. Instead, it follows a \logarithmic relationship. If the tax rate for an individual with an income of ₦1,000,000 is 20%, and the tax rate for an individual with an income of ₦5,000,000 is 30%, what is the tax rate for an individual with an income of ₦10,000,000?