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Question
Using contrapositive method prove that if n2 is an even integer, then n is also an even integers.
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Solution
Let p: n2 is an even integer.
q: n is also an even integer.
Also let ~ q is true i.e. n is not an even integer.
⇒ n2 is not an even integer .....[∵ Square of an odd integer is odd]
⇒ ~ p is true.
Hence, ~ q is true ⇒ ~ p is true.
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