Multiple Attacks with a Ranged weapon

Sorry if this has come up before but I am about to kill my DM now because of this.

How is ranged combat with multiple attacks worked out?

Example our Ranger has a BaB of +12 +6 and no rapid shot. Would he get 2 attacks with his bow or just one?

and if you don't need rapid shot what is the point of the feat?

2; giving an extra atack (bringing his total to 3)

With a BAB of +12 the attacks should be +12/+7/+2. Or if you meant his total attack bonus was +12 his second should be five lower (unless for some reason he's using say MW arrow for the first attack and a normal arrow for the second).

However, the purpose of rapiud shot is to give one additional attack. So if one's BAB is normally +8/+3. With Rapid shot you fire at +6/+6/+1.

Iterative attacks are at -5, so it should be +12/+7, or +11/+6, or some other correct value

Anyway , in order to have two attacks, you need a Base Attack Bonus of at least +6, regardless of any bonuses you get from dex or weapon.

Rapid Shot lets you take more than one attack per round (with both attacks at -2 to hit) even if your BAB isn't high enough to have two attacks - and if it is, you get an extra attack.

So without Rapid Shot, your ranger with the +12 to hit bonus would have two attacks, at +12 and +7 - and with Rapid Shot, he'd get an extra attack, for three attacks at +10, +10 and +5. (one extra attack at his maximum to hit bonus -2, and his normal two attacks at -2 to hit).

In each case, he could only make more than one attack with a full attack action.