The test is fairly easy if you have studied American history or have studied for the test. The reason for the test is not only so foreigners wishing to become citizens to know the history and the basics of our government but to show they have a commitment to learn something about the country the want to be a part of.
If my memory on the stats is correct, people required to take the test pass with a score of 95% or greater or fail with a score of 30% or less.