Taken from a Facebook page:
“When only 3 people pass your test, that says something about your teaching.”
I absolutely agree with that kid. I sometimes make tests that are harder than I expected, (actually I regularly do this despite my best efforts) but if I ever write a test that only 3 people pass, it will probably be time to retire. The test should reflect what I taught.
And I had better have taught more than three people in the room.