If you had 1000g of water (1 L) and added 360g of solute, the resulting solution would occupy a volume > 1L.
So if 1L of solution weighs 1360g, that means some amount of water < 1000g has been mixed with some amount of solute > 360g. But how much, we don't know without further information.
And by the way, even if it was 1000g water + 360g solute, that wouldn't be 36% solute. It would be 360/1360 = 26.5% solute.
(Borek, OP said "Aq" not "Ag")