1. Let's clarify the problem and identify what "b" refers to in the context. 2. Review the original problem statement and the solution steps for part b. 3. Check the calculations and logic used in part b carefully. 4. Identify the mistake or incorrect step in the solution for b. 5. Correct the error by recalculating or reanalyzing the problem. 6. Present the corrected answer for part b with detailed explanation. If you provide the original problem or the solution steps, I can help pinpoint and fix the error in part b.