Been on many forums, never saw such a brainless system.
If you must have an image with 6 letters for EVERY post, no problems. But don't ask TWO ADDITIONAL stupid questions like "Lazarus backwards" and "1+2". That just wastes our time, irritates everyone and doesn't add any protection against bots (since answers are always the same).
This is not anti-bot system. It's the anti-human system.