They are all correct. You can interchangeably use '이랑/랑' and '하고' in speech. And I'd like to add some more details regarding your question. 1. noun ending in a consonant + 이랑 / noun ending in a vowel + 랑 : 이랑/ 랑 is used in speech. e.g. 동생이랑 / 친구랑 2. noun + 하고 : 하고 is mostly used in speech. e.g. 동생하고/ 친구하고 3. noun ending in a consonant + 과 / noun ending in a vowel + 와 : 과/와 is more used in formal setting including writing e.g. 동생과 / 친구와

이랑 and 하고is actually same. So you can use it whenever or whatever you want. Example)의자하고 책상 의자랑 책상 Both sre right and make sense!

Disclaimer: I'm not a native speaker. First, just to make sure we're on the same page, the particle is (이)랑. I think you made a typo, since ㅣ and ㅏ are next to each other on the keyboard. Next, these two particles are largely interchangeable. I've heard that 랑 is slightly less formal, but it's certainly not rude. Also 하고 isn't necessarily formal. If you read academic texts or news articles, the most common particle is 과/와, so both 하고 and 랑 have a spoken feeling. My personal advice is that as a beginner, the best return on investment for your time would be not to worry about a possible subtle difference between these two particles and rather to practice acquiring new vocabulary and getting used to sentence structures. You'll work out these kinds of subtle differences through lots of exposure =)