OCR Further Statistics 2024 June — Question 6

Exam BoardOCR
ModuleFurther Statistics (Further Statistics)
Year2024
SessionJune
TopicPermutations & Arrangements
TypeSpecific items together

6 A bag contains 6 identical blue counters and 5 identical yellow counters.
  1. Three counters are selected at random, without replacement. Find the probability that at least two of the counters are blue. All 11 counters are now arranged in a row in a random order.
  2. Find the probability that all the yellow counters are next to each other.
  3. Find the probability that no yellow counter is next to another yellow counter.
  4. Find the probability that the counters are arranged in such a way that both of the following conditions hold.
    • Exactly three of the yellow counters are next to one another.
    • Neither of the other two yellow counters is next to a yellow counter.
    • Explain whether the answer to part (d) would be different if the yellow counters were numbered \(1,2,3,4\) and 5 , so that they are not identical.