Ask Marilyn Dec. 25, 2011: A drug test is done on employees, with a fourth of them selected at random every three months. "What's the likelihood of being chosen over the course of a year?"
Marilyn's answer: "The probability remains 25 percent, despite the repeated testing. . . . Goes against your intuition, doesn't it?"
Clearly, Marilyn stopped consulting her panel of mathematicians in the early nineties.