Ms. reynolds, the math teacher, was disappointed to announce that only 22% of her 68 students passed an exam. how many students failed the test?

Either a student passes an exam or fails it. that means the percentage of students who pass plus the percentage of students who fail must add to 100%. this also means that if 22% pass, then 78% fail. there are 68 students total and 78% fail so the number of students failing is:
(78/100)(68) = 53.04 which is approximately 53 students.

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