In 2020, Elizabeth has a total income of $140,000, and no deductions. Suppose that she has tax credits in two categories – basic personal and spousal. Suppose that her spouse has an income of $5,000. 

(a) How much income tax does the couple have to pay for this year? 

(b) What are Elizabeth's marginal tax rates for interest, capital gain and dividend income? 

(c)  Suppose instead that the couple's income (i.e., $140,000 + $5,000 = $145,000) is divided evenly between them (i.e., each person makes $72,500). How much income tax does the couple have to pay?

(d)  Calculate Elizabeth's marginal tax rates for interest, capital gain and dividend income based on her income in (c).