I need help with B.

Isabel, a calendar-year taxpayer, uses the cash method of accounting for her sole proprietorship. In late December she received a $30,000 bill from her accountant for consulting services related to her small business. Isabel can pay the $30,000 bill anytime before January 30 of next year without penalty. Assume her marginal tax rate is 40 percent this year and next year, and that she can earn an after-tax rate of return of 4 percent on her investments a. What is the after-tax cost if Isabel pays the $30,000 bill in December? After-tax cost 18,000 b. What is the after-tax cost if Isabel pays the $30,000 bill in January? Use Exhibit 31. (Round your answer to the nearest whole dollar amount.) After-tax cost c. Based on requirements a and b, should Isabel pay the $30,000 bill in December or January? O December Januarv. EXHIBIT 3-1 Present Value of a Single Payment at Various Annual Rates of Return Year 4% 5% 6% 7% 8% 9% 10% 11% 12% 1 962 952 943 .935.926 917 .909 .901 893 2 .925 907 890 873 857 842 .826 .812 .797 3 889 864 840 816 .794 .772 .751 .731 .712 4 855 823 .792 .763 .735 .708 683 659 .636 5 822 784 .747 .713 .681 650 621 593 567 6 .790 .746 .705 666 630 .596 .564 .535 .507 7 .760 .711 .665 .623 .583 .547 .513 .482 .452 8 731 677 627 .582 .540 .502 467 434 404 9 .703 645 .592 544 500 460 424 .391 .361 10 676 .614 558 .508 463 422 .386 .352 .322 11 .650 .585 .527 475 429 .388 .350 .317 .287 12 625 .557 497 444 .397.356 .319 .286 .257 13 601 .530 469 415 368 .326 .290 .258 .229 14 .577 505 442 .388340 .299 .263 .232 .205 15 .555 481 417 .362 .315 .275.239 .209 .183