Many people consider the practice of medicine to be more of an art than a science. But there are numerous ways in which a better understanding of the mathematical underpinnings of medicine can make you a much better—or at least a much more informed—patient. While almost all physicians are trained in the use of evidence-based medicine, most pretty much forget all about it once they graduate from medical school. You can do better.

Your Challenge:

Answer the following questions about medicine with actual numbers, looking up statistics as needed and showing your work. If multiple readers answer correctly, we’ll draw one winner. If no one nails every correct answer, the person who gets closest will win!

THE PRIZE: an Amherst T-shirt. Send your answers to

  1. If we take a random group of 1,000 50-year-old women, how many will be expected to die of breast cancer in the next 10 years? If we screen those 1,000 women with mammograms every two years for a decade, how many fewer women might be expected to die of breast cancer?

  2. A recent study found that 0.5 percent of women ages 50 to 69 have breast cancer. One woman in that age group goes in for a screening mammogram. She gets a call that it’s “positive” and needs to come back for a further workup. After that positive screen, what is the percent chance that she really has breast cancer, and what’s the percent chance that she does not?

  3. Your child has an ear infection, and you’re thinking about asking for antibiotics to treat it. How many ear infections does a pediatrician need to treat with antibiotics to prevent one serious complication? How many do they need to treat with antibiotics to reduce one child’s pain within 24 hours? Within two to seven days? Finally, how many do they need to treat with antibiotics to have one child get a side effect, like vomiting, diarrhea or a bad rash?

Last Quarter's Answers

An Amherst College t-shirt
Anyone who saw the RBG movie figured out that the “Legal Legend” in the Summer 2018 Contest is Ruth Bader Ginsburg. She was a federal judge when Amherst gave her an honorary doctorate of laws in 1991, praising her “scrupulous impartiality.”

The contest’s “Soulful Singer” is Nina Simone, who in 1977 received an honorary doctorate of music. “You are a giant in music,” her citation reads, “a personal and professional witness to the black experience in America in all its pain and, yes, all its triumph.”

The “Media Maven” is Washington Post publisher Katharine Graham, awarded a doctorate of humane letters in 1987. I was excited to learn of her honor, because I’ve been a Post subscriber for most of my adult life. I grew up watching my parents read Graham’s newspaper at breakfast.

Twelve readers answered correctly. The randomly selected winner is George Freeman ’71, executive director of the Media Law Resource Center. While Amherst magazine can’t bestow honorary degrees, we have full authority to send him the Amherst T-shirt of his choosing.