This problem has multiple parts but I need help with the las

3. Robert maintains a server farm with 20 identical computers. For convenience, these computers are labeled C1,C2,.,Cn. A software virus has infected exactly 3 machines, and every computer is equally likely to be affected by the virus. (a) 0.5 pt What is the probability that computer C1 is infected? (b) 1 pt What is the probability that computers C and C2 are both infected? (c) 1 pt What is the probability that computer C or computer C2 (or boths affected? (d) 1 pt A job is submitted to the server farm, and it requires 4 computers. What is the d) 1 pt - A job is submitted to the server farm, and it requires 4 computers. What is the probability that this job runs on 4 virus-free computers if it is randomly assigned to four machines in the farm? (e) 1.5 pt Once assigned tasks, a virus free machine is twice as likely to finish before an infected computer. Computer Ci and computer C2 are assigned tasks at the same time. What is the probability that Ci is one of the three infected computers given that it finishes after C2

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