A museum archives contain 13 ancient scrolls that require restoration: 6 from the Dynasty Era, 4 from the Classical Era, and 3 from the Hellenistic Era. The head curator selects two scrolls at random, one after the other without replacement, to be sent to a specialist lab.
Construct a complete tree diagram to illustrate all the possible outcomes and the associated conditional probabilities for the selection of the two scrolls. State your probabilities clearly.
Determine the exact probability that the curator selects one Classical Era scroll and one Hellenistic Era scroll.
200 exam-style questions on OCR A Level Maths 2.3 Probability, covering 2.3.1 Mutually exclusive and independent events, 2.3.2 Diagrams to assist probability calculations, 2.3.3 Conditional probability (A-level only), 2.3.4 Conditional probability from first principles (A-level only), and 2.3.5 Modelling with probability. Each one has a worked solution and a mark scheme showing where the marks go.