Aggron is a Steel/Rock-type Pokemon, so its weaknesses are Fighting (4x the damage), Water, and Ground-type attacks. (4x the damage as well.)
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
super effective is bug
psychic pokemons and attacks are super effective
Steel is super effective against rock type pokemon.
Flying and Psychic are super effective against fighting
Lightning is super effective against water. I hope this helps.
Ghost & Flying. I believe that's it! Not dark or bug because although they're super-effective against Psychic, they are not-effective against Fighting. And not Psychic, because though it's super-effective against Fighting, it's not-effective against Psychic.
Water and Grass attacks are super effective against Onix.
super effective is bug
psychic pokemons and attacks are super effective
Bug Type and Fighting Type moves are super effective against it.
Steel is super effective against rock type pokemon.
Rock, electric, ice, and psychic types are super effective against Crobat.
normal type Pokemon are not super effective against any type.
Bug types are super effective against Dark, Grass and Psychic (x2) in Generation II-onward. In Generation I, they were super effective against Grass, Poison and Psychic.
Actually the Ground is the only super effective type against thunder type pokemon.