c# sum of the sums in the array

Got stuck on quite simple problem in my code. I need to count what I would call a nested sums of an array. Let’s take as an example the array:
[1,2,2,3,6]
I want to sum them as:

0 + 1 = 1
1 + 2 = 3
1 + 2 + 2 = 5
1 + 2 + 2 + 3 = 8
1 + 2 + 2 + 3 + 6 = 14

sum = 1 + 3 + 5 + 8 + 14 = 31

Edit:
I tried to do it with stack, but it failed

            int sums = 0;
            Stack<int> sum = new Stack<int>();

            for (int i = 0; i < queries.Length; i++)
            {
                sum.Push(queries[i]);
            }

            for (int i = 0; sum.Count != 0; i++)
            {
                if(i != 0)
                {
                    sums += sum.Pop();
                }
            }

>Solution :

You can do this much more efficiently and more easily, by multiplying each value by its reversed index + 1

For example, using LINQ

int[] arr = { 1, 2, 2, 3, 6 };
var result = arr.Reverse().Select((val, i) => val * (i + 1)).Sum();

Note that .Reverse on an array (or other Collection<T>) does not actually move any items, it just reads them backwards. So this is therefore an O(n) operation, as opposed to your original solution which is O(n² / 2)

dotnetfiddle

You can also do this procedurally, this is almost the same as @aminrd’s answer.

int[] arr = { 1, 2, 2, 3, 6 };
var result = 0;
for (var i = arr.Length - 1; i >= 0; i--)
    result += arr[i] * (i + 1);