Haru is a self-employed cash-method, calendar-year taxpayer, who made the following cash payments related to his business this year.

Calculate the after-tax cost of each payment assuming Haru has a 37 percent marginal tax rate.

b. $800 of interest on a short-term loan incurred in September and repaid in November. Half of the loan proceeds was used immediately to pay salaries and the other half was invested in municipal bonds until November.

c. $600 for office supplies in May of this year. Haru used half of the supplies this year, and he will use the remaining half by February of next year.

d. $450 for several pairs of work boots. Haru expects to use the boots about 80 percent of the time in his business and the remainder of the time for hiking. Consider the boots to be a form of clothing.