(a) Harry is arranging his spell books on the shelf of his dormroom. He has 6 different books of fire spells, and 5 differentbooks containing ice spells. In how many possible ways can Harryarrange his spell books, if no two books of the same kind can beadjacent?

(b) Ron is arranging his spell books on the shelf of his dormroom. He has 5 different books of fire spells and 5 different bookscontaining ice spells. In how many possible ways can Ron arrangehis spell books, if no two books of the same kind can beadjacent?

(c) Hermione is arranging her spell books on the shelf of herdorm room. She has 6 different books of fire spells, 3 differentbooks containing ice spells, and 3 different books for lightningspells. In how many possible ways can Hermione arrange her spellbooks, if no two books of the same kind can be adjacent?