Задание №74605 ЕГЭ Английскому языку

Correct the mistakes

1. This isn't the train on that I normally travel.
2. The letter that I opened it wasn't for me.
3. I didn't know the name of the man helped me.
4. Rupert knows the family who's house is for sale.
5. Einstein who failed his university entrance exam discovered relativity.
6. The person we talked to were very friendly.