OCR S1 2009 June — Question 7

Exam BoardOCR
ModuleS1 (Statistics 1)
Year2009
SessionJune
TopicCombinations & Selection

7 Three letters are selected at random from the 8 letters of the word COMPUTER, without regard to order.
  1. Find the number of possible selections of 3 letters.
  2. Find the probability that the letter P is included in the selection. Three letters are now selected at random, one at a time, from the 8 letters of the word COMPUTER, and are placed in order in a line.
  3. Find the probability that the 3 letters form the word TOP.