what type of problem can be solved using the least common multiple?

We've had many questions similar to this:

A doughnut shop gives away a free cup of coffee to each 10th customer. It also gives away a free doughnut to each 15th customer. If the present customer gets both a free doughnut and cup of coffee, which numbered customer will get both?

The least common multiple (LCM) is a mathematical concept commonly used in problems involving multiples and divisors. It helps us find the smallest common multiple of two or more numbers. The LCM is especially useful in situations where we need to find a common denominator or determine when two or more events will occur simultaneously.

Here are some examples of problems that can be solved using the LCM:

1. Fractions: When adding or subtracting fractions with different denominators, we need to find a common denominator. The LCM of the denominators will give us the smallest common multiple to use as the new denominator.

2. Time: Suppose two events occur at different intervals. By finding the LCM of the intervals, we can determine when these events will happen simultaneously again.

3. Scheduling or planning: If you have multiple tasks or events that repeat at different intervals, finding the LCM can help you determine when they will align or when the next occurrence will happen.

4. Building a fence: Imagine you want to build a fence around your garden with multiple sections. To find the length of the fence needed, you can calculate the LCM of the length of each section.

In general, any situation that involves finding the smallest common multiple or synchronizing events can benefit from using the LCM.