[NHT2]

Greetings, this is my first post.

After careful consideration I decided to come here for help. I have run into a wall in my Japanese language class. I have been assigned to answer five questions:

1. だこにいきましたか.
Where did you go?
2. てんきはどうでしたか.
How was the weather?
3. だれといきましたか.
Who did you go with? (I think)
4. ひこうきのきつぷはいくらでしたか.
How much was the airplane ticket?

I have the answer to the first one.

1. わたしは Washington D.C. にいきました.
I went to Washington D.C. (Again, I am not sure if that is the correct answer)

I have an attempt at the second one.
2. てんきはあついかったです.
The weather was hot. (I am certain that is not correct)

I do not know how to say "I went with (someone)" in Japanese. The 3rd one is giving me the most trouble.

The final question is giving me a bit of a problem. For one, I am not sure if I should convert 500 U.S. dollars to yen, or figure out how to say "500 American dollars" in Japanese.

This is my attempt:
4. ひこうきのきつぷはごまねんです.
The Airplane ticket cost 50,000 Yen.

Any help would be greatly appreciated.