CAIE S1 2011 June — Question 6

Exam BoardCAIE
ModuleS1 (Statistics 1)
Year2011
SessionJune
TopicBinomial Distribution
TypeMost likely value (mode)

6 The probability that Sue completes a Sudoku puzzle correctly is 0.75 .
  1. Sue attempts \(n\) Sudoku puzzles. Find the least value of \(n\) for which the probability that she completes all \(n\) puzzles correctly is less than 0.06 . Sue attempts 14 Sudoku puzzles every month. The number that she completes successfully is denoted by \(X\).
  2. Find the value of \(X\) that has the highest probability. You may assume that this value is one of the two values closest to the mean of \(X\).
  3. Find the probability that in exactly 3 of the next 5 months Sue completes more than 11 Sudoku puzzles correctly.