Prestige classes and Base Attack Bonuses

[TheBulletKnight]

So, I don't know if I'm blind or stupid, but I haven't been able to find this information in the books.

So, lets say you're an Alchemist 12/ Master Chymist 3. From Alchemist, you get a base attack bonus of +9/+4. From Master Chymist, you get +3. Do you get a BAB of +12/+7/+2 or +12/+4?

Edit:
Now lets say you retrain and so you become an Alchemist 10/Master Chymist 10. Do you get a base attack bonus of +17/+12/+7/+2?

[Joe loves Rules]

12/7/2

[Blakmane]

12/+7/+2.

And yes, your second example is correct.

[TheBulletKnight]

Thank you very much. It makes prestiging seem a lot better, now that I know this.