(i) Let us assume that p is not true. ∴ Sum of an irrational and a rational number is not irrational. ⇒ There exists an irrational number a and a rational number b such that a + b is not irrational. ⇒ a + b = c (say) is a rational number. ⇒ a = c – b ⇒ a is rational But a is irrational, which is a contradiction. So, our supposition is wrong. Thus, p is true. (ii) Suppose n > 3 but $n^2$ ≯ 9 ⇒ $n^2$ ≤ 9 ⇒ $n^2$ – 9 ≤ 0 ⇒ (n – 3)(n + 3) ≤ 0 ⇒ –3 ≤ n ≤ 3 which is a contradiction as n > 3. So our supposition is wrong. If n is a real number with n > 3, then $n^2$ > 9.