What is the least common multiple of 25 and 28 and 30?

Answer 1

The LCM of 25, 28, and 30 is 2100.

Let's take the following three numbers: 25, 28, and 30.

Using prime factorization, the factors for each number are, as follows:

• 25 => 5 * 5
• 28 => 2 * 2 * 7
• 30 => 2 * 3 * 5

Now, these can be rewritten, as follows:

• 25 => 5 squared
• 28 => 2 squared * 7
• 30 => 2 * 3 * 5

For LCM, you take the HIGHEST power of EACH factor. For this example, you take the highest powers for the 2, 3, 5, and 7 factors.

That would be:

• 2 squared (or 4)
• 3
• 5 squared (or 25)
• 7

Multiple these four factors together (4 * 3 * 25 * 7) to get 2100.

Answer 2

It is: 2100