Choose the correct answer (and or but)

1. It was a difficult exam, and but I passed it.
2. She worked hard and but made a lot of money.
3. He looks too serious, and but in fact, he's so much fun.
4. I was against the new project, and but I accepted to help.
5. He was late and but wasn't allowed to get in.
6. It was very expensive, and but I bought it.
7. She was very poor, and but she never asked for help.
8. He wanted to eat sushi for dinner, and but he couldn't find a Japanese restaurant.
9. He stopped talking and but lit a cigarette.
10. I wanted to attend the meeting, and but I couldn't because I was very ill.