If the income tax rate changes from 30% to 40% on income over Rs30,000 and a person’s income is Rs 31,000 then her marginal tax rate is ? June 3, 2019 – by admin If the income tax rate changes from 30% to 40% on income over Rs30,000 and a person’s income is Rs 31,000 then her marginal tax rate is ? A. 30% B. 10% C. 70%D. 40%