In succession of the paper I wrote last year, here we give some troubles in teaching and their solutions occured during the Software Science Experiment II course, which is opened for the 5th semester in the Department of Software Science. One of the subjects of the experiment course is understanding the fundamentals of PCM (Pulse Code Modulation). They deal with the sampling theorem and bandwidth of communications. Some students are still not familiar with Fourier analysis while the explanation of the sampling theorem is done at the frequency region. Typical mistakes and their settlements are given.