How would minecraft work(how many fps aprox.) on a laptop with these specifications?

You don't need a good GPU for Minecraft. Minecraft purely relies on CPU power, but I'm not sure, but the i3-3120M should work at at least 30 FPS.

You might want to get more RAM, you only have 2GB left after your graphics card uses it and minecraft needs mostly RAM to run since its Java Based. But other then that you should get a solid 60 FPS on medium-Max settings.