Least Common Multiple of 3 Numbers

Finding the least common multiple (lcm) of three numbers is similar to finding the lcm of 2 numbers.

To find the least common multiple (lcm) of three numbers

We begin by psting the first few multiples of the three numbers.

Then we look for the common multiples of all the numbers.

The first common multiple of the numbers would be their least common multiple.

Find the least common multiple of 6, 10, 15

Solution

Step 1:

The multiples of 6, 10 and 15 are as follows

Multiples of 6 = 6, 12, 18, 24, 30, 36, 42, 48, 54, 60…

Multiples of 10 = 10, 20, 30, 40, 50, 60, 70, 80…

Multiples of 15 = 15, 30, 45, 60, 75, 90…

Step 2:

Some common multiples of the three numbers are 30, 60...

Step 3:

The first common multiple of 6, 10 and 15 is 30, which is their least common multiple (lcm)

Find the least common multiple of 9, 12, 24

Solution

Step 1:

The multiples of 9, 12 and 24 are as follows

Multiples of 9 = 9, 18, 27, 36, 45, 54, 63, 72

Multiples of 12 = 12, 24, 36, 48, 60, 72

Multiples of 24 = 24, 48, 72, 96

Step 2:

The first common multiple of 9, 12 and 24 is 72, which is their least common multiple (lcm)