I found this nice article on the BBC website.
It’s no great surprise that medics fail this particular test, since the teaching they receive aimed at understanding probability is generally poor.
I’ve included a graphical explanation below:
If this doesn’t make sense, do get in touch (especially if you work as a doctor of medicine!)
Patrick Andrews has a PhD in Mechanical Engineering from Heriot-Watt University and an MSc in Neuroscience from the University of Cambridge.
A former Chartered Engineer and Chartered Mathematician, Patrick has worked in management consultancies and high-tech startups, and in academia as a postdoc in Applied Mathematics at Cambridge and a maths lecturer at De Montfort University.
Patrick is the father of three delightful (but not uniformly mathematical!) daughters.