Linq Compound selection

Question

How can i combine two arrays in to a single array during compound selection ( without using Union ) ( The question was asked at interview).

    var num1 = new int[] { 12, 3, 4, 5 };
    var num2 = new int[] { 1, 33, 6, 10 };

I tried as

    var pairs = from a in num1 from b in num2  select new {combined={a,b}};

Expected: combined need to be {12,3,4,5,1,33,6,10}

Answer 1

num1.Concat( num2 );

I'm not sure if there is a related LINQ keyword.