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).
The multiples of 3 up to 30 are: 3,6,9,12,15,18,21,24,27,30.The multiples of 5 up to 30 are: 5,10,15,20,25,30.The only common multiples are 15 and 30.The LCM is: 30
15 and 30
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.
30, 60, 90, 120, 150, ...
15, 30 and 45