What is the least common denominator of 1/4, 3/7, 1/11

Alright. One way you can do this is to list multiples of each denominator:

1/4:
4, 8, 12, 16, 20, 24, 28, 32, 36 and so on

3/7:
7, 14, 21, 28, 35, 42, 49, 57, 63

1/11;
11, 22, 33, 44, 55, 66, 77, 88

Keep going until you see the least common denominator!

Now an easier way to do this is by multiplying all of the numbers in the denominator then get the factors:

4*7*11 = 308

And since those are not divisible by a whole number (besides 4 but 308 won't be divisible by 2*7*11)

Therefore 308 is the least common denominator.