Question

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

Answer 1

Resposta:

81 números

Explicação passo-a-passo:

11, 12, 13, 14, 15, 16, 17, 18, 19

21, 22, 23, 24, 25, 26, 27, 28, 29

31, 32, 33, 34, 35, 36, 37, 38, 39

41, 42, 43, 44, 45, 46, 47, 48, 49,

51, 52, 53, 54, 55, 56, 57, 58, 59,

61, 62, 63, 64, 65, 66, 67, 68, 69,

71, 72, 73, 74, 75, 76, 77, 78, 79,

81, 82, 83, 84, 85, 86, 87, 88, 89,

91, 92,93, 94, 95, 96, 97, 98, 99