LINQ to find the closest number that is greater / less than an input

Question

Suppose I have this number list:

List = new List(){3,5,8,11,12,13,14,21}

Suppose that I want to get the closest number th

Answer 1

This is my answer

List myList = new List() { 3, 5, 8, 11, 12, 13, 14, 21 };
    int n = 11;
    int? smallerNumberCloseToInput = (from n1 in myList
                                    where n1 < n
                                    orderby n1 descending
                                    select n1).First();

    int? largerNumberCloseToInput = (from n1 in myList
                                    where n1 > n
                                    orderby n1 ascending
                                    select n1).First();