I'm having a hard time understanding how to derive the # ways to do things. (a) A course has 4 sections with no limit on how many can enrol in each section. 3 students each pick a section at random. (i) Specify Sample Space S (64?) (ii)Find the probability that they all end up in the same section (3C1 /64 = 3/64??) (iii) Find the probability that they all end up in different sections (3P3/64 = 6/64 ??) (iv) Find the probability that nobody picks section 1 ( 3C2 * 2! / 64 = 6/64??) (b) Repeat (a) in the case where there are n sections and s students. Can someone please help me derive their answers of how they get the # of ways to do each. Thanks a lot!