By giving a counter-example, show that the statement is false : p : If n is an odd positive integer, then n is prime. - Noon Academy

By giving a counter-example, show that the statement is false :
p : If n is an odd positive integer, then n is prime.

RS Agarwal Maths Class 11 Mathematical Reasoning

By giving a counter-example, show that the statement is false :
p : If n is an odd positive integer, then n is prime.

Let us take a odd positive integer n = +9
Even though (+9) is an odd positive integer, It is divisible by 3.
To be a prime number, a number must only have itself and 1 as its factors. Since 9 has
3 as its factor too, it is not a prime number in spite of being an odd positive integer.
∴ The given statement p is false.

i

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