An airfoil includes a platform that has platform leading and trailing ends, lateral side faces, and inner and outer faces. An airfoil portion extends outwardly from the inner face of the platform. The airfoil portion includes airfoil leading and trailing ends and side walls that join the airfoil leading and trailing ends. The platform includes a cooling passage that has an inlet at a forward location, outlet slots at the platform trailing end, and an intermediate passage portion that extends from the inlet to the outlet slots. The intermediate passage portion includes a common manifold region that feeds the outlet slots. The platform includes a rib that is elongated in a length direction between the platform leading and trailing ends. The rib divides two of the cooling passages such that the two cooling passages are fluidly unconnected with each other in the platform.