Nobody is born with an encyclopaedic knowledge of how to solve maths problems. Of course, a student who is comfortable with analytical reasoning and arithmetic has a headstart on others but an efficient learning method is equally important in building your understanding.

The value of a tutor is that through practice questions they should be able to identify the gaps in the student's understanding that are holding them back. By focusing their attention on these gaps the learning experience is tailored to the specific needs of the individual allowing them to progress faster than otherwise possible. If the tutor addresses the problems effectively then the tutee should build up a broader understanding of the subject, be able to spot where they are going wrong and have the confidence to ask questions or read around the subject themselves. In time a student will be able to practice questions (maths is like a sport in that you become better through practice not reading in a manual how to solve problems) where they previously found difficulty and progress to more complex areas. 

Quite simple really!!!