Which of the following formulas would find the surface area of a right cone where s is the slant height r is the radius la is the lateral area and ba is the base area?

It's the fourth one...no wait, it's the first one....oh hang on, it could be the second.

Oh dear, looks like my psychic abilities are failing again...without the list of formulae I can't tell you which one it is.

But I can tell you the surface area of a cone:

surface_area_cone = area_base + lateral_surface_area

= ba + la

= πr2 + πrs

= πr(r + s)