CSATNumber System & SeriesArithmetic of Prime Numbers2023

Consider the following in respect of prime number p and composite number c. 1. p+c/p-c can be even. 2. 2p + c can be odd. 3. pc can be odd. Which of the statements given above are correct?

A

1 and 2 only

B

2 and 3 only

C

1 and 3 only

D

1, 2 and 3

Correct Answer: Option D

Explanation

We use the 'Existence Proof' method by testing specific numbers. The key is to remember that Composite numbers can be Odd (e.g., 9, 15). 1. **Check Statement 3 ($pc$ can be odd):** For a product to be odd, both numbers

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