Sets 2

2 marks · Hard

Express the set of all positive integers greater than 4 and less than or equal to 15 in set-builder notation.

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\{ x : 4 < x \leq 15,\ x \in \mathbf{N} \}

Also accept: { x \in \mathbf{N} : 4 < x \leq 15 }; { x : x \in \mathbf{N},\ 4 < x \leq 15 }; { x : x \in \mathbf{N},\ 5 \leq x \leq 15 }

Common mistakes: Using wrong inequality signs; Omitting the restriction that x is a natural number

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Marking points

M1 · 1 mark · Writes correct restriction using inequalities or equivalent form

A1 · 1 mark · Includes correct use of the set of natural numbers, i.e.,

Worked solution

The set consists of positive integers greater than 4 and less than or equal to 15.