You're just realizing that now? How long was it like that?
You just figured this out now? How many hours was it like that?
ーYou're just realizing that now? How long was it like that?
「今気がついたの？どのくらいその状態だったの？」
realize で「気がつく」
How long was it like that? で「どのくらいその状態だったの？」
ーYou just figured this out now? How many hours was it like that?
「今気がついたの？何時間その状態だったの？」
figure out で「〜であると分かる」という意味なので、洋服が前後ろ逆だと分かる＝気がつくというニュアンスで使えます。
How many hours was it like that? で「何時間その状態だったの？」となります。
ご参考まで！
カナダ 
