Question

Determinati numerele pare de forma: ab5c

Answer 1

Toate numerele care respecta urmatoarele cconditii:
$a\in\{1;2;3;4;5;6;7;8;9;\} \\ b\in\{0;1;2;3;4;5;6;7;8;9\} \\ c\in\{0;2;4;6;8\}$

In total sunt 450 de numere.

Answer 2

ab5d = nr par => c = { 0,,2,4,6,8} 
                          a = {1,2,3,4,5,6,7,8,9}
                          b = { 1,2,3,4,5,6,7,8,9}
ab5d = { 1150,1250,1350,1450,1550,1650,1750,1850,1950, 1252,1254,1256,1258,1352,1354,1356,1358,1452,1456,1454,1458,1552,1554,1556,1558,1652,1654,1656,1658,1752,1754,1756,1758,1852,1854,1856,1858,1952,1954,1956,1958,2150,2154,2152,2156,2158,2250,2254,2252,2256,2258,2350,,2352,2354,2356,2358,................8550,8552,8554,8556,8558,................9850,9852,9854,9856,9858,9950,9952,9954,9956,9958}