Răspuns :
404,414,424,434,454,464,474,484 si 494,de 10 ori intalnim cifra 4
Defapt de 20 de ori: 400, 404, 414, 424, 434, 440, 441, 442, 443, 444, 445, 446, 447, 448, 449, 454, 464, 474, 484, 494
404,414,424,434,454,464,474,484 si 494,de 10 ori intalnim cifra 4