What, exactly is your question? Do you know what the "Poisson Distribution" is? If not, there is, of course, no way you could do these problems! If you do, they should not be very difficult.

In addition to reviewing the "Poisson Distribution", I recommend you go back and reread the problem. What you give as the first problem, "1.Complaints through e-mails are received randomly on average once every 48hours.Show that the probability that the number of complaints through e-mails in one year is equal r" makes no sense because there is no "r" defined in the problem itself! Did you accidently cut off part of the question?