Answer:
6
Step-by-step explanation:
Maybe you want a suitable common denominator for 2/3 and 1/6. If so, you can observe that 3 is a factor of 6, so 6 is a suitable common denominator.
2/3 = (2/3)·(2/2) = (2·2)/(3·2) = 4/6
The equivalents, 4/6 and 1/6, share a common denominator of 6.