C# & .Net

Given the following array, write the link Query in the following questions

int[] A = {2, 3, 4, 10, 100}

1. given an int input k, write the LINQ query required to combine the members of the list A with itself k times.
2. How to find all values greater than the average of the items in the list
3. How to find the number of elements in the result in (2) .