CAIE S1 2019 November — Question 7

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2019
SessionNovember
TopicPermutations & Arrangements
TypeArrangements with adjacency requirements

7
  1. Find the number of different ways in which the 9 letters of the word TOADSTOOL can be arranged so that all three Os are together and both Ts are together.
  2. Find the number of different ways in which the 9 letters of the word TOADSTOOL can be arranged so that the Ts are not together.
  3. Find the probability that a randomly chosen arrangement of the 9 letters of the word TOADSTOOL has a T at the beginning and a T at the end.
  4. Five letters are selected from the 9 letters of the word TOADSTOOL. Find the number of different selections if the five letters include at least 2 Os and at least 1 T .
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