I HAVE DONE THIS MATH PROBLEM AT LEAST TWENTY TIMES, BUT MY ANSWER...

24. - BAI TAP ON THI TN VA DAP AN
BAI TAP ON THI TN VA DAP AN
24. I have done this math problem at least twenty times, but my answer is wrong according to the answer key. A. The answer in the book should be wrong!B. The book needn't have a wrong answer.C. There is a wrong answer in the book.D. The answer in the book must be wrong!