not friendly, and showing little interest in other people in a way that seems slightly rude

I didn't mean to be offhand with her - it's just that I was in such a hurry. 我希望我没有表现出怠慢了她——我不过是太匆忙了。

without looking for information and without thinking carefully; immediately

I can't quote the exact statistics for you offhand, but they're there for you to see in the report. 我不能马上就给你举出确切的数据，不过这些数据可以在报告中查到。