5. Prove that 2 is irrational by using a contrapositive-based proof. Hint: if a number n is rational, then n may be expressed as the ratio of two whole numbers p and q, i.e., n = p/q; furthermore it can be assumed that p and q are in lowest terms. Examples of fractions not in lowest terms: 4/8 and 2/4, whereas 1/2 is in lowest terms.