Answer:
Always when you try to answer a question like this. Start by listing the multiples of each of the two numbers and then take the least common multiple. Here is the illustration.
2 multiples: 2, 4, 6, 8, ...
3 multiples: 3, 6, 9, 12, ...
We can see here the least common multiple is 6.
We do the exact same thing with the other pair of numbers.
8 multiples: 8, 16, 24, 32, 40, 48, 56, 64, 72, 80
9 multiples: 9, 18, 27, 36, 45, 54, 63, 72, 81
L.C.M of 8/9 : 72.
64 multiples: 64, 128, 192, 256, 320, 384, 448, 512, 576, 640, .... , 5184
81 multiples: 81, 162, 243, 324, 405, 486, 567, 648, 729, 810, .... , 5184
LCM of 64/81 : 5184.
10 multiples: 10, 20, 30, .... , 270
27 multiples: 27, 54, 81, .... , 270.
LCM of 10/27 : 270.
Hope this made sense:)