Write down the following statement in words.

$$q \Rightarrow p$$

Write down, in words, the contrapositive statement of $q \Rightarrow p$.

Determine whether your statement in part (a) is logically equivalent to your statement in part (b). Justify your answer.

If Eva is losing weight then Eva is on a diet     (A1)(A1)     (C2)

Notes: Award (A1) for If… then…

     For Spanish candidates, only accept “Si” and “entonces”.

     For French candidates, only accept “Si” and “alors”.

     For all 3 languages these words are from the subject guide.

     Award (A1) for correct propositions in correct order.

[2 marks]

If Eva is not on a diet then she is not losing weight     (A1)(A1)     (C2)

Notes: Award (A1) for “not on a diet” and “not losing weight” seen, (A1) for complete correct answer.

     No follow through from part (a).

[2 marks]

The statements are logically equivalent     (A1)(ft)

The contrapositive is always logically equivalent to the original statement     (R1)(ft)

OR

A correct truth table showing the equivalence     (R1)(ft)     (C2)

Note: Follow through from their answers to part (a) and part (b).

[2 marks]