(Time) + mae ni usage to express "ago"

[xmoonsirenx]

Can someone please check if my sentences are correct. I am practicing the usage of "mae ni". Such as " X hours ago"

She opened the window an hour ago.
-kanojo wa ichi-ji kan mae ni mado wo akemashita.

I studied 5 hours ago.
-watashi wa go-ji kan mae ni benkyou shimashita.

I went to aya's house two days ago.
-watashi wa ni nichi kan mae ni aya san no ie ni ikimashita.

I saw koji two weeks ago at the mall.
-nishuukan mae ni mooru de wa koji wo mita.


hontou ni arigatou gozaimasu!

[ericf]

Yep, that looks pretty good. The only thing I'd change is ni nichi kan; 二日間 happens to be pronouced ふつかかん (futsuka kan) though the meaning is exactly the same.