West Mountain Radio, an electronics firm specializing in equipment interfaces, had been in a marginal tax bracket of 39 percent and then this year had an increase in taxable income of \($150,000.\) Their increase in taxes was exactly \($54,750.\) For each of the following, determine the smallest amount that meets the conditions given above.

a. What was their taxable income last year?

b. What was their total income tax this year?