PHI 103
posted by Anonymous .
Mrs. Orlof teaches two history classes, one in the morning and one in the afternoon. Yesterday she gave the same test to both classes. Anyone who failed the test must take a retest. Since a greater percentage of students who took the morning test failed the test than students who took the afternoon test, more of Orlofâ€™s morning history students than afternoon history students will have to take the retest.
The conclusion above is not necessarily valid because

A larger percentage doesn't mean more students. The morning class may be larger than the afternoon class.