I need to solve these problems and know how to solve them . Thank you.

2. Campus Tours Student volunteers take visitors on a tour of 7 campus buildings. How many different tours are possible? (Assume order is important.) 3. Inspecting Restaurants How many different ways can a city health department inspector visit 5 restaurants in a city with 10 restaurants? (Assume order is important.) 4. How many different 4-letter permutations can be formed from the letters in the word "decagon". 5. Ticket Selection How many different ways can 4 tickets be selected from 50 tickets if each ticket wins a different prize? 6. If no restrictions are imposed on ordering, the number of possible arrangements of 4 mathematics, 5 chemistry, and 4 physics books in a line equals 7. If books of each group be arranged within themselves in the order math - chemistry - physics, the number of possible arrangements of 3 mathematics, 2 chemistry, and 2 physics books in a line equals. 8. How many words can be formed by rearranging the letters of the word composed