How long will it take for the concentration of a to decrease from 0. 850 m to 0. 205 for the reaction a → products? (k = 0. 0882 m⁻¹s⁻¹).

It depends on the subject for me. some exams are easier than others so i usually go through it and answer questions i know based on my general knowledge, then double check after. going through the lesson can a lot  because the exams can be  very lesson-specific, but sometimes they are ridiculously long so a lot of people don't take the time. i did find that, when i went through the lessons, i was making 100's on my exams vs strictly using + the internet and  i make 90's.