Markov chain weather transitions

Questions about day-to-day weather transitions where the probability of each day's weather depends only on the previous day's weather (Q6421).

2 questions · Moderate -0.3

2.03b Probability diagrams: tree, Venn, sample space2.03c Conditional probability: using diagrams/tables2.03d Calculate conditional probability: from first principles
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CAIE S1 2020 November Q4
9 marks Moderate -0.3
4 In a certain country, the weather each day is classified as fine or rainy. The probability that a fine day is followed by a fine day is 0.75 and the probability that a rainy day is followed by a fine day is 0.4 . The probability that it is fine on 1 April is 0.8 . The tree diagram below shows the possibilities for the weather on 1 April and 2 April.
  1. Complete the tree diagram to show the probabilities. 1 April \includegraphics[max width=\textwidth, alt={}, center]{33c0bd01-f27b-424c-a78a-6f36178bc08c-08_601_405_706_408} 2 April Fine Rainy Fine Rainy
  2. Find the probability that 2 April is fine.
    Let \(X\) be the event that 1 April is fine and \(Y\) be the event that 3 April is rainy.
  3. Find the value of \(\mathrm { P } ( X \cap Y )\).
  4. Find the probability that 1 April is fine given that 3 April is rainy.
OCR MEI S1 2010 June Q7
18 marks Moderate -0.3
7 One train leaves a station each hour. The train is either on time or late. If the train is on time, the probability that the next train is on time is 0.95 . If the train is late, the probability that the next train is on time is 0.6 . On a particular day, the 0900 train is on time.
  1. Illustrate the possible outcomes for the 1000,1100 and 1200 trains on a probability tree diagram.
  2. Find the probability that
    (A) all three of these trains are on time,
    (B) just one of these three trains is on time,
    (C) the 1200 train is on time.
  3. Given that the 1200 train is on time, find the probability that the 1000 train is also on time. 3
  4. Write any calculations on page 5. \includegraphics[max width=\textwidth, alt={}, center]{091d6f43-ad01-4849-9f3c-3e58349aa169-4_2276_1490_324_363}