(b): We have, (a,b)R(c,d) ⇒ 3ad − 7bc is an even integer. For reflexive : (a,b)R(a,b) ⇒ 3ab − 7ab = − 4ab, Which is an even integer. For symmetric, (a,b)R(c,d) ⇒ 3ad − 7bc is an even integer. ⇒ 3ad − 7bc + 4bc + 4ad is also an even integer ( ∵ even + even = even number ) ⇒ 7ad − 3bc is an even integer ⇒ 3cb − 7da is also an even integer ⇒ (c,d)R(a,b) For transitive, (a,b)R(c,d) and (c,d)R(e,f) ⇒ 3ad − 7bc and 3cf − 7de is an even integer.For a = 2,b = 5,c = 6,d = 8,e = 9,f = 1 3af − 7bc = 3 × 2 × 1 − 7 × 5 × 9 = 6 − 315 = − 309 which is not an even integer. ∴ Given relation is not transitive.