Will you loose marks for getting the final answer with little work. For example a question is supposed to take 10min but I took 3min and got the final answer right with little work?
If your method and answer are correct, I wouldn't think so. The times given are only guidelines, some questions will take less time, some will take more.
There's a special way the marking is done. They have scales and when you get down to one step you get a certain amount of marks until you get the answer. You may loose marks if they are crucial steps you skipped but it might only be like 2 marks.
If your method is correct and you have rounded correctly, put in appropriate units and answered the question you will get full marks