Let p, q, r and s be distinct positive integers. Let p, q be odd and r, s be even. Consider the following statements : 1. (p − r)²(qs) is even. 2. (q − s)q²s is even. 3. (q + r)²(p + s) is odd. Which of the statements given above are correct?

Statement 1: (p−r) is odd−even=odd, (p−r)² is odd; qs is odd×even=even; odd×even=even. Correct. Statement 2: (q−s) is odd−even=odd, q² is odd, s is even; odd×odd×even=even. Correct. Statement 3: (q+r) is odd+even=odd, (q+r)² is odd; (p+s) is odd+even=odd; odd×odd=odd. Correct. All three statements are correct.