When one of the numbers is a multiple of the other.
There is no "greatest common multiple" of any two numbers. Whatever their product is, it can be multiplied by any positive integer to yield an even greater number that is also a multiple of the first two. Thus, the number of multiples is infinite.
The LCM of 15 and 25 is 75. The least common multiple of two numbers is the product of the two numbers divided by their greatest common factor. The greatest common factor of 15 and 25 is 5. (See related question "What is the greatest common factor of 15 and 25?" for this calculation.) So, the least common multiple is 15 x 25 ÷ 5 = 75. The least common multiple (LCM) is often also called the lowest common multiple or smallest common multiple. Keep in mind that these different terms all refer to the same thing: the smallest positive integer which is a multiple of two or more numbers.
There is an infinite number of common multiples for 3 and 15. A common multiple of any two or more numbers is any number into which each of two or more numbers can be divided evenly (zero remainder). However, the least or lowest common multiple (LCM) of 3 and 15 is 15.
There is none because the Least Common Denominator (or LCD) refers to the Least Common Multiple (LCM) of the denominators of two or more fractions or mixed numbers. Even if you converted your whole numbers (x) to their fraction equivalents (x/1), the LCD would always be 1.
Yes, two natural numbers always have a least common multiple.
Yes, the least common multiple of two numbers is always divisible by those numbers' greatest common factor.
yes
Yes - if two numbers share no common factors (besides 1) the least common multiple will be the product of the numbers.
Yes. If A and B are any two whole numbers then A*B is a common multiple. Then either A*B is the least common multiple of A and B or one of its factors is.
Sometimes, not always.
Yes.
No, this will find a common multiple, but not always the least. For example, 2 and 4 have a least common multiple of 4 but if you multiply them you get 8. In fact, the LCM will only be the product of two numbers if the numbers have no common factors. We call numbers with no common factors relatively prime.
The product of all pairs of prime numbers is always the least common multiple of the two prime numbers.
You can always find a common multiple of two numbers by multiplying them together; it will not always be the least common multiple. As one counterexample, if one of the numbers is a multiple of the other, the first number is the LCM of the two. 9 x 3 = 27 The LCM of 9 and 3 is 9. 4 x 6 = 24 The LCM of 4 and 6 is 12.
There is always going to be a LCM. Just multiply the two numbers together to get the a common multiple if you cant find one because the two numbers multiplied together is a common multiple.
to find the least common multiple of two numbers you must list the factors then you can find out their least common multiple of the two numbers