a) 102, 132, 162, 192, 402, 432, 462, 492, 702, 732, 762, 792, 312, 612, 912, 342, 642, 942, 372, 672, 972
b) 200, 210, 220, 230, 240, 250, 260, 270, 280, 290, 205, 215, 225, 235, 245, 255, 265, 275, 285, 295
c) 1060, 1062, 1064, 1066, 1068, 1160, 1162, 1164, 1166, 1168, 1260, 1262, 1264, 1266, 1268, 1360, 1362, 1364, 1366, 1368, 1460, 1462, 1464, 1466, 1468, 1560, 1562, 1564, 1566, 1568, 1660, 1662, 1664, 1666, 1668, 1760, 1762, 1764, 1766, 1768, 1860, 1862, 1864, 1866, 1868, 1960, 1962, 1964, 1966, 1968 - in total 50
se schimba cifra de ordinul al IV-lea cu 2, 3, 4, 5, 6, 7, 8, 9. 50×9=450
