In the product \(ab\) of two numbers \(a\) and \(b\), if \(a\) is increased by \(1\) and \(b\) is decreased by \(1\), then their product will be \((a + 1)(b – 1)\).
(i) If so, what is the increase in product?
(ii) Will the product always increase? Interpret your answer.
(iii) Find three examples where the product decreases.