When the game says 2 x medium cannon 7.5 damage. Does it mean 2 x 7.5?

The first one; the DPS is per cannon and thus you can multiply it!

Thanks smarti. It seemed like a dumb question, like it was obvious. But I wanted to know conclusively from those that had looked at the stats or seen enough in game stats to realise.... i'd probably look at a ship with more of the same gun types that I could compare stats with the smaller ships for to realise the damage was listed as the same and therefore per gun. Easier to ask at this stage. Apprecaite your time.