Plz !

two submersibles, one red and one blue, started rising toward the surface at the same time. they each rose at a constant speed. the red submersible starts rising from an altitude of 80 meters below the surface. after 30 seconds, it was 60 meters below the surface. the following equation gives the altitude (in meters relative to the surface) of the blue submersible as a function of time (in seconds). a= -90 + 0.6t

which submersible started rising from a higher altitude?

which submersible rose faster?