blog2.cs

public IEnumerable<Books> AllHumor()
{
    return from book in BookCase.Books
           where book.genre.Humor == true
           select book;
}

public IEnumerable<Books> Fiction(IEnumerable<Books> sample)
{
    return from book in sample
           where book.Category == "Fiction"
           select book;
}

public IEnumerable<Books> Biography(IEnumerable<Books> sample)
{
    return from book in sample
           where book.Category == "Biography"
           select book;
}

var FunnyFiction = Fiction(AllHumor());
var FunnyBios = Biography(AllHumor());