Can someone help? I would really appreciate it if someone showed me how to work it out to get to the final answer in order to be able to answer similar upcoming questions. Thanks in advance :)

Problem:

Two taxi companies operate in Mathcity: Blackcabs and Yellowrides. 85% of the cabs in the city work for Blackcabs and are coloured black. The rest of the cabs in the city work for Yellowrides and are coloured yellow. A taxi was involved in a hit-and-run accident at night. A witness told the police that the taxi was yellow. The court carried out a series of tests of the reliability of the witness, asking her to identify the colour of a random sequence of taxis. The witness correctly identified each one of the two colours 80% of the time and failed 20% of the time.

Questions:

1 - What is the probability that the taxi involved in the accident was yellow?

2 - Karolina carries out a traffic survey in Mathdty. She sits at an interchange and notes the colour of the first six cabs that pass her. What number of yellow cabs is she most likely to observe?

What types of diagram can be used to represent the problem?

What assumptions did you make?