OCR MEI D2 2008 June — Question 1

Exam BoardOCR MEI
ModuleD2 (Decision Mathematics 2)
Year2008
SessionJune
TopicGroups

1
  1. The Plain English Society presents an annual "Foot in Mouth" award for "a truly baffling comment". In 2004 it was presented to Boris Johnson MP for a comment on the \(12 ^ { \text {th } }\) December 2003 edition of "Have I Got News For You":
    "I could not fail to disagree with you less."
    1. Explain why this can be rewritten as:
      "I could succeed in agreeing with you more."
    2. Rewrite the comment more simply in your own words without changing its meaning.
  2. Two switches are to be wired between a mains electricity supply and a light so that when the state of either switch is changed the state of the light changes (i.e. from off to on, or from on to off). Draw a switching circuit to achieve this. The switches are both 2-way switches, thus:
    \includegraphics[max width=\textwidth, alt={}, center]{88acde67-e22b-478a-9145-48abe931beff-2_127_220_895_1054}
  3. Construct a truth table to show the following. $$[ ( a \wedge b ) \vee ( ( \sim a ) \wedge ( \sim b ) ) ] \Leftrightarrow [ ( ( \sim a ) \vee b ) \wedge ( a \vee ( \sim b ) ) ]$$