Write the negation of the following statements:

(i) p: For every positive real number x, the number x – 1 is also positive.


(ii) q: All cats scratch.


(iii) r: For every real number x, either x > 1 or x < 1.


(iv) s: There exists a number x such that 0 < x < 1.

(i) The negation of the statement p is


It is false that for every positive real number x, the number x – 1 is also positive.


This can be rewritten as


There exists a positive real number x such that the number x – 1 is not positive.


(ii) The negation of the statement q is


It is false that all cats scratch.


This can be rewritten as


There is at least one cat that does not scratch.


(iii) The negation of the statement r is


It is false that for every real number x, either x > 1 or x < 1.


This can be rewritten as


There exists a real number x such that neither x > 1 nor x < 1.


(iv)The negation of the statement s is


It is false that there exists a number x such that 0 < x < 1.


This can be rewritten as


There does not exist a number x such that 0 < x < 1.


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