4.Assume Sarah is a cash-method calendar-year taxpayer. She made a $3,000 payment for next years property taxes on her place of business. What is the after-tax cost of this payment assuming she has a 25 percent marginal tax rate?

5.Assume Sarah is a cash-method calendar-year taxpayer. She made a $400 payment for dinner with out-of-town clients during contract negotiations. What is the after-tax cost of this payment assuming she has a 25 percent marginal tax rate?

6.Assume Sarah is a cash-method calendar-year taxpayer. She made a $2,500 contribution to the mayors re-election campaign. What is the after-tax cost of this payment assuming she has a 25 percent marginal tax rate?