A mobile game is available on three platforms. 60% of downloads are from the App Store, 25% from the Play Store, and 15% from a Web Download.
The probability that a download from the App Store results in a bug report is 1%. The probability that a download from the Play Store results in a bug report is 2%. The probability that a download from a Web Download results in a bug report is 6%.
Draw a tree diagram to show this information.
A download is selected at random. Find the probability it results in a bug report.
Given that a download resulted in a bug report, find the probability it was from the Play Store.
200 exam-style questions on OCR (MEI) A Level Maths 2.3 Probability, covering 2.3.1 Calculate the probability of an event, 2.3.2 Complementary events, 2.3.3 Expected frequency of an event, 2.3.4 Diagrams to calculate probabilities, 2.3.5 Mutually exclusive and independent events, 2.3.6 Add probabilities for mutually exclusive events, 2.3.7 Multiply probabilities for independent events, 2.3.8 Mutually exclusive and independent events (notation) (A-level only), 2.3.9 Venn diagrams for probabilities (A-level only), 2.3.10 Conditional probabilities (A-level only), and 2.3.11 Independence via conditional probability (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.