Use flavour multiplicities rather than physical bar identities

(a) A teacher wants to set a class test for 25 students. Each student receives the same questions, but in a different order. Find the least number of questions she must set.

(b) Sally has 12 chocolate bars: white 4, milk 3, dark 4 and hazelnut 1. She intends to give one bar each to three of her best friends in school.

(i) Find the number of ways she can do it.

(ii) One particular friend has a nut allergy and should not be given the hazelnut bar. Find the number of ways Sally can now give her friends the chocolates.