User interface language: English | Español

Date November 2012 Marks available 2 Reference code 12N.1.sl.TZ0.9
Level SL only Paper 1 Time zone TZ0
Command term Write Question number 9 Adapted from N/A

Question

Consider the following logic statements.

p: Carlos is playing the guitar

q: Carlos is studying for his IB exams

Write in words the compound statement \(\neg p \wedge q\) .

[2]
a.

Write the following statement in symbolic form.

“Either Carlos is playing the guitar or he is studying for his IB exams but not both.”

[1]
b.

Write the converse of the following statement in symbolic form.

“If Carlos is playing the guitar then he is not studying for his IB exams.”

[3]
c.

Markscheme

Carlos is not playing the guitar and he is studying for his IB exams.     (A1)(A1)     (C2)

Note: Award (A1) for “and”, (A1) for correct statements.

[2 marks]

a.

\(p\underset{\raise0.3em\hbox{$\smash{\scriptscriptstyle-}$}}{ \vee } q\)     (A1)     (C1)

[1 mark]

b.

\(\neg q \Rightarrow p\)     (A1)(A1)(A1)     (C3)

Notes: Award (A1) for implication, (A1) for the \(\neg q\), (A1) for both \(\neg q\) and \(p\) in the correct order. If correct converse seen in words only award (A1)(A1)(A0). Accept \(p \Leftarrow \neg q\). Accept \( - q\) for \(\neg q\).

[3 marks]

c.

Examiners report

In part (a) occasionally ‘if…then…’ was not seen but generally this was well done.

a.

Part (b) was also well done despite the dearth of previous testing of the exclusive or statement.

b.

Finding the converse of a statement in part (c) proved to be difficult for a significant number of candidates and incorrect answers of the form \(q \Rightarrow \neg p \) were more frequently seen than the correct answer. Such incorrect answers lost two marks.

c.

Syllabus sections

Topic 3 - Logic, sets and probability » 3.2 » Translation between verbal statements and symbolic form.
Show 48 related questions

View options