36 = (2^2)*(3^2)
The least common multiple is the product of the unique factors to the highest power that they appear in either of the pair of numbers. At least one of the numbers must have 2^2 = 4 as a factor, and at least one of them must have 3^2 = 9 as a factor. Possible choices for pairs that have 36 as their least common multiple include
{1, 36}, {2, 36}, {3, 36}, {4, 36}, {6, 36}, {9, 36},
{12, 36}, {18, 36}, {4, 18}, {12, 18}, {9, 12}, {4, 9}
The least common multiple is the product of the unique factors to the highest power that they appear in either of the pair of numbers. At least one of the numbers must have 2^2 = 4 as a factor, and at least one of them must have 3^2 = 9 as a factor. Possible choices for pairs that have 36 as their least common multiple include
{1, 36}, {2, 36}, {3, 36}, {4, 36}, {6, 36}, {9, 36},
{12, 36}, {18, 36}, {4, 18}, {12, 18}, {9, 12}, {4, 9}