Euler 1

/// <summary>

/// If we list all the natural numbers below 10 that are multiples of 3 or 5, we get 3, 5, 6 and 9.

/// The sum of these multiples is 23.Find the sum of all the multiples of 3 or 5 below 1000.

/// </summary>

var val = Enumerable.Range(0, 1000).Sum( o => ( (o % 3 == 0) || (o % 5 == 0) ) ? o : 0 );