Solve Our Challenge and Get a Free Ticket for ML Prague — updated with correct answers

Barbora Hanousková
code.kiwi.com
Published in
2 min readFeb 8, 2019

We're partnering with Machine Learning Prague again! Thanks to that you can get a free ticket to the biggest European practical conference about ML, AI and Deep Learning applications.

On 22–24 February 45 world experts will bring outperforming solutions that you can learn through practical talks. You can get an overview of the complete program on the conference website.

How to get a free ticket?

Go through the following assignment and find out the correct answers.

Suppose you’re waiting in the airport hall where your flight is announced. It’s departing from terminal C.

Unfortunately, the airport is shortly after reconstruction and navigation signage is still being replaced. As a traveller at an unfamiliar airport overwhelmed by all the kiosks, people and shops all sections of the airport look the same to you. Luckily, there is a map of the airport.

You are in a rush and have no other option, but to choose your path randomly. Moving between any two connected airport sections distinguished by colours takes 5 minutes. You need to be at your terminal in 10 minutes.

The questions and tasks are the following:

  1. What is the probability of you catching your flight on time?
  2. What would be the probability of you catching your flight if it was 5 minutes delayed (meaning that you have 5 extra minutes)?
  3. Calculate determinant of the transition matrix
  4. Create the transition diagram
You are in a rush and have no other option, but to choose your path randomly.

The winner and the correct answers

Congratulations go to Max who sent us an explanatory solution and received the ticket. Here are the correct answers:

  1. The overall probability is 1/3.
  2. The overall probability is 1/2.
  3. The determinant of the transition matrix is 1/12.

Short feedback on the received solutions.

Many of you made the mistake of not adding the probabilities of both successful paths on question #2 ( Airport Hall -> A -> C of 1/3 _and_ Airport Hall -> A -> B -> C of 1/6 ).

In #3 the zero-diagonal may have thrown you off but if you used Sarrus’ rule correctly, you would have ended up with one non-zero sub-determinant.

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Barbora Hanousková
code.kiwi.com

Professional daydreamer, occasional poet and a little bit of everything | UX Writer and ex-editor of code.kiwi.com