There are infinitely many multiples of 9 and it is not possible to add them all.
9,18
Each common multiple of 9 and 10 occurs exactly once (in the list of common multiples), so there is no common multiple that occurs the most. All common multiples of 9 and 10 are the multiples of their least common multiple which is 90.
Itself and any multiples of 9
There are an infinite number of multiples of any number. Therefore, it is impossible to list all the multiples of 3 and 4. A list of the first 10 multiples: Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40
9
There are infinitely many multiples of 9 and it is not possible to add them all.
That's an infinite list.
That's an infinite list: All multiples of 9.
There are infinitely many of them and so it is not possible to list them. They are numbers of the form 9*k where k is an integer.
9,18
There are infinitely many multiples of 9 and 21 so it is impossible to list them. One of their multiples is 9*21 = 189.
Each common multiple of 9 and 10 occurs exactly once (in the list of common multiples), so there is no common multiple that occurs the most. All common multiples of 9 and 10 are the multiples of their least common multiple which is 90.
9, 18, 27.
Itself and any multiples of 9
There are infinitely many of them so I will not bother trying to list them.
There are an infinite number of multiples of any number. Therefore, it is impossible to list all the multiples of 3 and 4. A list of the first 10 multiples: Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 Multiples of 4: 4, 8, 12, 16, 20, 24, 28, 32, 36, 40