common multiple
There are no common multiples of one number. Two or more are needed to answer this question.
A common multiple is used to compare the multiples of two or more numbers - a single number cannot have any common multiples.
Any number can be a common multiple of two or more fractions. The concept of common multiples is useful only in the context of multiples of integers.
A single number cannot have any common multiples - you need two or more numbers to compare.
Those are known as "common multiples". The smallest POSITIVE of these common multiples is called the "least common multiple".
There is an infinite number of common multiples for 13 and 17. A common multiple of any two numbers is any number into which each of two or more number can be divided with zero remainder.
There is an infinite number of common multiples for 6 and 10. A common multiple of any two numbers is any number into which each of two or more number can be divided with zero remainder.
There is an infinite number of common multiples for 21 and 40. 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).
There is an infinite number of common multiples for 40 and 84. 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).
There is an infinite number of common multiples for 150 and 2,250,000. 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).
There is an infinite number of common multiples for 5 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).