The arithmetic sequence $a, a+d$, $a+2 d, a+3 d, \ldots, a+(n-1) d$ has the following properties:

- When the first, third, and fifth, and so on terms are added, up to and including the last term, the sum is 320 .
- When the first, fourth, seventh, and so on, terms are added, up to and including the last term, the sum is 224 .

What is the sum of the whole sequence?
(A) 656
(B) 640
(C) 608
(D) 704
(E) 672