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Date November 2016 Marks available 2 Reference code 16N.1.sl.TZ0.5
Level SL only Paper 1 Time zone TZ0
Command term Complete Question number 5 Adapted from N/A

Question

Consider the following logic propositions. 

     \(p\): Sandi gets up before eight o’clock

     \(q\): Sandi goes for a run

     \(r\): Sandi goes for a swim

Write down in words the compound proposition

[3]
a.

Complete the following truth table.

N16/5/MATSD/SP1/ENG/TZ0/05.b

[2]
b.

On a morning when Sandi does not get up before eight o’clock, use your truth table to determine whether \(p \Rightarrow (q{\text{ }}\underline  \vee  {\text{ }}r)\) is a tautology, contradiction or neither.

[1]
c.

Markscheme

If Sandi gets up before eight o’clock then Sandi (either) goes for a run or goes for a swim, but not both.     (A1)(A1)(A1)     (C3)

 

Note:     Award (A1) for If …… then ……, (A1) for all propositions in the correct order, (A1) for “… or … but not both” (do not accept “either” as a replacement for “but not both”).

 

[3 marks]

a.

N16/5/MATSD/SP1/ENG/TZ0/05.b/M     (A1)(A1)(ft)     (C2)

 

Note:     Award (A1) for correct \((q{\text{ }}\underline  \vee  {\text{ }}r)\) column, and (A1)(ft) for their correct \(p \Rightarrow (q{\text{ }}\underline  \vee  {\text{ }}r)\) column. Follow through from their \((q{\text{ }}\underline  \vee  {\text{ }}r)\) column.

 

[2 marks]

b.

tautology     (A1)(ft)     (C1)

 

Note:     Follow through from part (b).

 

[1 mark]

c.

Examiners report

[N/A]
a.
[N/A]
b.
[N/A]
c.

Syllabus sections

Topic 3 - Logic, sets and probability » 3.1
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