Răspuns:
a) 27x : 2
x € {0, 2, 4, 6, 8}
27x € {270, 272, 274, 276, 278}
b) 542x : 2
x € {0, 2, 4, 6, 8}
542x € {5420, 5422, 5424, 5426, 5428}
c) 4xx : 2
x € {0, 2, 4, 6, 8}
4xx € {400, 422, 444, 466, 488}
d) xxx : 2
x € {2, 4, 6, 8}
xxx € {222, 444, 666, 888}