(d)13x + 1 < 2z and z + 3 = 5y2 Combining the two equations, we get 13x + 7 < 10 y2 Let us consider x = 1 and y = 2, then we have 13×1+7<10×(2)2⇒20<40 when ( x = 1) < ( y = 2), the given inequality is satisfied. Hence choice (b) and (c) are eliminated. Now, we consider x = 4 and y = 3, we have 13×4+7<10×(3)2,59<90 Hence, option (a) is also ruled out. Therefore, option (d) is best answer.