40, 80, 120
30
Any multiple of 30.
It is: 120
30, 60 and 90
The common multiples of 3,4, and 10 would be all the multiples of 60. 60, 120, 180, 240... all the way to 6000.
Common denominators. These are called "common multiples". For example, multiples of 4 are: 4,8,12,16,20,24 ... . Multiples of 6 are: 6,12,18,24,30,36 ... . The numbers on both lists are the common multiples and they include: 12,24,36, ... . Specifically, the smallest number in any such list of common multiples (12 in this example) is known as the Least (or Lowest) Common Multiple or LCM.
To find the numbers between 10 and 50 that are multiples of both 3 and 5, we need to find the numbers that are multiples of the least common multiple of 3 and 5, which is 15. The multiples of 15 between 10 and 50 are 15, 30, and 45. Therefore, there are 3 numbers between 10 and 50 that are multiples of both 3 and 5.
5
15,18,21,24,27,30,33,36,39,42,45,48,51,54,57,60,63,66,69,72,75,78,81,84,87,90,93,96,99
1 11 10
10, 20 and 30
4, 6 and 10