That really depends greatly on your knowledge level and preparation.
If you go in without studying the material, you will fail. That is guaranteed.
If you have no aeronautical knowledge about things such as reading sectional charts, reading METAR reports, knowing what different weather and cloud formations signify, crew resource management, weight and balance,etc... then it is not a trivial matter. You need to know these topics and how to interpret the question, to get the correct answer.
If you do have some knowledge already, I would still suggest studying to see how much you don't know and what you need to brush up on. I have my Private Pilot's license and I was familiar with the materials already. So I studied for a few hours and scheduled the test.
The nice thing is that if you are prepared, you will generally pass. I don't think the questions were geared to trick me, although some questions could have been worded much better. Multiple choice and one answer is typically way wrong! So the odds are really in your favor if you go in prepared.
BRING A MAGNIFYING GLASS ! I did not do so and had a tough time with some of the sectionals because the lighting was terrible in the testing center. I felt like I was taking the test in candlelight.
Also SEARCH is your friend. Search for 107 in the forum here and you will find a lot of information.