What is the least common multiple (LCM) of 4 and 5?

What is the least common multiple (LCM) of 4 and 5?

• A. 9
• B. 20
• C. 15
• D. 10

Answer: (B)

The least common multiple (LCM) of two numbers is the smallest multiple that is evenly divisible by both numbers. To find the LCM of 4 and 5, we start by identifying the multiples of each number. The multiples of 4 are: 4, 8, 12, 16, 20, 24, ... The multiples of 5 are: 5, 10, 15, 20, 25, ... Next, we look for the smallest number that appears in both lists of multiples. The number 20 is present in both the multiples of 4 and the multiples of 5, making it the smallest number that satisfies the condition of being a multiple of both. Thus, the least common multiple of 4 and 5 is 20, as there are no smaller common multiples in both sets.

The least common multiple (LCM) of two numbers is the smallest multiple that is evenly divisible by both numbers. To find the LCM of 4 and 5, we start by identifying the multiples of each number.

The multiples of 4 are: 4, 8, 12, 16, 20, 24, ...

The multiples of 5 are: 5, 10, 15, 20, 25, ...

Next, we look for the smallest number that appears in both lists of multiples. The number 20 is present in both the multiples of 4 and the multiples of 5, making it the smallest number that satisfies the condition of being a multiple of both.

Thus, the least common multiple of 4 and 5 is 20, as there are no smaller common multiples in both sets.