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Check Whether the Statement Are True Or Not: Q : If X, Y Are Integers Such that Xy is Even, Then at Least One of X and Y is an Even Integer.

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Question

Check whether the statement are true or not: 

 q : If xy are integers such that xy is even, then at least one of x and y is an even integer.

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Solution

 p: If x and y are integers such that xy is even, then at least one of x and y is an even integer.
Let q and r be two statements.
Here,
qxy is an even integer.
r: At least one of x and y is an even integer.
Let r be not true.
Then, r is not true.
It is false that at least one of x and y is an even integer.
Now,
x and y are odd integers.
x = 2m +1 and = 2n + 1 for some integers and n.

⇒ xy =(2m + 1)(2n + 1)

⇒ xy = 2(2mn + n) + 1
So, xy is not an even integer. Thus, xy is not true.
Hence, the statement is true.

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Chapter 31: Mathematical reasoning - Exercise 31.6 [Page 28]

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R.D. Sharma Mathematics [English] Class 11
Chapter 31 Mathematical reasoning
Exercise 31.6 | Q 2.2 | Page 28

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