What is the lcm of 4 and 5

Answer: 20

Step-by-step explanation: To find the least common multiple or lcm of 4 and 5, begin by listing the first few multiples of each number.

Multiples of 4

1 * 4 = 4

2 * 4 = 8

3 * 4 = 12

4 * 4 = 16

5 * 4 = 20

Notice that we skipped 0 * 4 in our list of multiples.

That's because 0 * 4 is 0 and our least common multiple can't be 0.

When listing the multiples of 5, it's a really good idea to keep an eye on the list of multiples for 4 so that we'll notice when we find a least common multiple.

Multiples of 5

1 * 5 = 5 ← isn't a multiple of 4

2 * 5 = 10 ← isn't a multiple of 4

3 * 5 = 15 ← isn't a multiple of 4

4 * 5 = 20 ← is a multiple of 4

Notice that the 20 is the first multiple that appears in both lists. We can stop here because all other multiples that we find will be greater than 20 and we want the least common multiple.

So the least common multiple or lcm of 4 and 5 is 20.