How can we write the Linq query for selecting a set of first authors in the books containing the word 'our' in the title, using local variables?

Answer:

IEnumerable<Author> firstAuthors = from b in books
let title = b.Title
let authors = b.Authors
where title.Contains("our")
select authors[0];

foreach (Author author in firstAuthors)
Console.WriteLine("Author - {0}, {1}",
author.LastName, author.FirstName);