What is the least common multiple of 40 and 20?
Understand the Problem
The question is asking for the least common multiple (LCM) of the numbers 40 and 20. To solve this, we will find the multiples of both numbers and identify the smallest multiple that they share.
Answer
The least common multiple of 40 and 20 is $40$.
Answer for screen readers
The least common multiple (LCM) of 40 and 20 is $40$.
Steps to Solve
- List the multiples of each number
Start by listing the first few multiples of both 40 and 20.
Multiples of 40: $40, 80, 120, 160, 200, \ldots$
Multiples of 20: $20, 40, 60, 80, 100, 120, 140, 160, 180, 200, \ldots$
- Identify the common multiples
Next, we will identify the multiples that are shared by both lists.
Common multiples of 40 and 20: $40, 80, 120, 160, 200, \ldots$
- Determine the least common multiple
The least common multiple (LCM) is the smallest number that appears in both lists of multiples.
From the common multiples, the smallest is $40$.
The least common multiple (LCM) of 40 and 20 is $40$.
More Information
The least common multiple is a fundamental concept in mathematics often used in solving problems involving fractions and finding common denominators. It’s also useful in scenarios such as scheduling where events repeat at different intervals.
Tips
- A common mistake is to select the largest common multiple instead of the smallest. Always be sure to look for the least common multiple.
- Another mistake is to forget to list enough multiples to ensure the least one is found; make sure to write enough multiples down.
