If your investors have agreed 30% based on the post-money valuation, and a 10% post-money options pool, then your example is correct. Or, to be entirely accurate:
- The investors would have 500/(1000+666) = 30.01%
- The options pool 166/(1000+666) = 9.96%
- All founders combined 1000/(1000+666) = 60.02%
(Percentage values rounded off to two decimals.)
However, this blindly assumes that you already have negotiated this result, or are in a position to actually negotiate this. There are other points that need to be settled, see for example the Venture Hacks article "The Option Pool Shuffle". I assume you meant the question as a hypothetical example, just to see a basic math example of issuing new shares.