Studying effectively means that you studied before but your studying wasn't effective and you get low marks, which mean you didn't know how to study effectively by studying the things that effect the exams directly and that spotlight on the next exam.

You may solved exams before but that wasn't effective for your next exam, as it came in a total different way, don't blame the exam that it didn't come like you expected, but blame yourself for not practising for the exam in the right way, because the teacher or the doctor won't ever bring a total different exam, but he can change the type of questions he write on the exam's paper, for example instead of writing "Give reason: Why do fish keep wake up?" he may write "Tell me about fish night life." as fish do not sleep and there wasn't anything in the book related to fish night life, then the answer will be completely the same although both questions is totally different, so take care of this trick. (Know more study tips for exams)

Also you may say ah-ha during solving the exam as you think that there was a trick in question, but the question was direct, as there was a title in the book talking about fish night life but you didn't study it, so you thought the question is talking about why fish keep wake up, which is here a different problem as you read the question right but it's your fault not to study this part in the subject.

how to study effectively

You may totally answer a different answer for such two questions which have only one answer, that may lead you to take very much less marks for your answer if it wasn't zero, so read the question in the exam carefully because 75% from answering right is reading the question right, and this is the practical part of studying effectively.

Are you in need to study fast as you are close to exams, 3 Hours (your exams guide) is there to help you.

Stronger Students contain article that will totally help you studying for your exams, even if your are close to it.

How to study for exams

How to study properly in college

Learn how to study

How to study smarter not harder

The Ultimate University Guide (Book)

3 Hours Your Exams Guide Book (Book)