In a math class with 20 students, a test was given the same day that an assignment was due. There were 11 students who passed the test and 15 students who completed the assignment. There were 9 students who passed the test and also completed the assignment. What is the probability that a student chosen randomly from the class failed the test and did not complete the homework?

In a math class with 20 students, a test was administered the same day an assignment was due. There were 11 students who passed the test and 15 students who completed the assignment. There were 9 students who passed the test and also completed the assignment. What is the probability that a randomly selected student in the class will fail the test and not complete the assignment? number (passed or returned to duty)

= 11 + 15 - 9

= 17

but there were 20 students so we failed 3 and didn't turn in the assignment

You can achieve the same result using a Venn diagram