Unlike some introductory textbooks, a complete, officially published "Solutions Manual" for the entire Bransden and Joachain text is not widely distributed to students. Usually, these manuals are restricted to to ensure that problem sets remains an effective tool for evaluation.
If a Bransden and Joachain problem seems too dense, look at Introduction to Quantum Mechanics by David Griffiths. Griffiths often explains the same concepts with more intuition, making the rigorous "work" in Bransden easier to follow. Unlike some introductory textbooks
If you are struggling with a specific problem and can't find a legitimate PDF, try these strategies: Unlike some introductory textbooks
Check if your library has the "Instructor's Edition" on reserve. Some institutions allow students to consult these within the library walls. A Word on Academic Integrity Unlike some introductory textbooks