Find the least common denominator (LCD) of

1/20 and 11/30

60

Step-by-step explanation:

LCD (1 / 20, 11 / 30) = LCM (20, 30) = 22*3*5 = 60

1 / 20 = 3 / 60

11 / 30 = 22 / 60

60

Step-by-step explanation:

To find the LCD, all you have to do is find the least common multiple (LCM) of the two denominators.

The fractions are already reduced, so you have to find the LCM of 20 and 30. The LCM of 20 and 30 is 60.

To find the LCM:

20 and 30 are easy numbers, so you can just list the multiples out.

20: 20, 40, 60, etc.

30: 30, 60

The lists both have 60, so the LCM is 60.

Another way is to prime factorize the two numbers.

20: 2^2*5

30: 2*3*5

Then, take the non-repeating factor from the second number (3) and multiply that by 30, which is 60.