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Date May 2009 Marks available 1 Reference code 09M.1.sl.TZ1.2
Level SL only Paper 1 Time zone TZ1
Command term State Question number 2 Adapted from N/A

Question

Consider the two propositions p and q.

p: The sun is shining     q: I will go swimming

Write in words the compound proposition

\(p \Rightarrow q\) ;

[2]
a.

Write in words the compound proposition

\(\neg p \vee q\).

[2]
b.

The truth table for these compound propositions is given below.

Complete the column for \( \neg p\).

[1]
c.

The truth table for these compound propositions is given below.

State the relationship between the compound propositions \(p \Rightarrow q\) and \(\neg p \vee q\) .

[1]
d.

Markscheme

If the sun is shining then I will go swimming.     (A1)(A1)     (C2)

 

Note: Award (A1) for “if…then” and (A1) for correct order.

 

[2 marks]

a.

Either the sun is not shining or I will go swimming.     (A1)(A1)     (C2)


Note: Award (A1) for both correct statements and (A1) for “either” “…or”.

 

[2 marks]

b.

     (A1)     (C1)

[1 mark]

c.

They are (logically) equivalent.     (A1)     (C1)


Note: Do not accept any other answers.

 

[1 mark]

d.

Examiners report

The most common error was poor use of the “If...then” connective.

a.

Confusion between “and” and “or” was rare, however, the use of implication in this part was a little too common.

b.

Precise, correct terminology was expected in this part.

c.
[N/A]
d.

Syllabus sections

Topic 3 - Logic, sets and probability » 3.4 » Logical equivalence.

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