The taxi problem revisited

January 1998

In this issue's article "Image analysis - a modern application of mathematics", Julian Stander introduced the idea of using Bayes' Theorem to update our beliefs based on new information.

We can use Bayes' Theorem to solve the taxi problem in Issue No. 2 (see "The taxi problem" ):

A witness sees a crime involving a taxi in Carborough. The witness says that the taxi is blue. It is known from previous research that witnesses are correct 80% of the time when making such statements. The police also know that 85% of the taxis in Carborough are blue. What is the probability that a blue taxi was involved in the crime?

Solution

Add new comment

Not clearly stated/cannot be solved.

Comment

Don't spend your time on this one. See /content/taxi-problem for a corrected problem formulation /content/yet-more-taxis

Maths in a minute

Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.

Balancing the equations of a low carbon energy network

Generating electricity without the use of fossil fuels is not just an engineering and industrial challenge, it is also a huge mathematical challenge.
Living Proof: The irrational diary of Clara Valentine

In this podcast author Coralie Colmez shares insights into her novel The irrational diary of Clara Valentine.
Mathematical summer fun

We talk to early career mathematicians who spent some of their summer holiday solving problems posed by industry — such as how to blend a perfect smoothie!
Meat free meat with maths

Don't like plant-based meat alternatives, but want to spare animals and the environment? There's hope on the horizon, aided by a good helping of maths.
Maths in a minute: Inverse problems

Inverse problems are mathematical detective problems. They can help solve crimes, are used in medical imaging, and much more.

Tweets by plusmathsorg