Question

Quantos números de 2 algarismos diferentes podemos escrever com os algarismos 1, 2, 3, 4, 5, 6, 7, 8 e 9

Answer 1

Resposta: 72 números

12, 13, 1 4, 15, 16, 17, 18, 19

21, 23, 24, 25, 26, 27, 28, 29

31, 32, 34, 35, 36, 37, 38, 39

41, 42, 43, 45, 46, 47, 48, 49

51, 52, 53, 54, 56, 57, 58, 59

61, 62, 63, 64, 65, 67, 68, 69

71, 72, 73, 74, 75, 76, 78, 79

81, 82, 83, 84, 85, 86, 87, 89

91, 92, 93, 94, 95, 96, 97, 9