The knowledge test is a written multiple-choice test. You must get 32 out of 40 correct answers to pass the test. If you do not pass, there may be a waiting period before you can retest. A passing score is good for two years.
You must be at least 15-1/2 years old to take the state written test
You must have a Washington state ID number, which is on a Washington state ID card or permit. You don't need an ID card, but the ID number is required and is free to get one. If you don't have an Washington state ID number, you can learn how to get one here.