can anyone help with this question

(b) There were 3 persons (say A, B and C) infected with a particular virus. This virus can be easily transmitted when such an infected person comes into close contact with an unprotected healthy person. Person A interacts with no one else, Person B interacts once with each of 3 unaffected persons, and Person C interacts once with each of 5 unaffected persons. Assuming that there are no further interactions outside of these 11 persons, and that the healthy persons can interact up to once with each other, but only within their group of 3 and 5 respectively, how many different possible ways can result in one of the 8 healthy persons becoming infected with the virus? [You may use any approach towards finding this solution] (6 marks) (c) In how many ways can a medical task force team of 10 persons be selected from a contingent of 15 doctors and 10 senior nurses, if there must be 6 doctors in the team