30 and 60 (if you count 60)
The LCM is 60.
All multiples of 840 are common multiples of 60 and 280
They are 30, 60 and 90.
30 60 90
30, 60, 90, 120, 150, ...
They have to be multiples of 15 so all of them will be multiples of 3. They all have to be even so you are left with 30, 60, 90
60 1*60 = 60 4*15 = 60
The multiples of 15 are 15, 30, 45, 60, 75 and so on. For them to be common, they need to be compared to another set of multiples.
The multiples of 20 are 20, 40, 60, 80, 100, 120... The multiples of 30 are 30, 60, 90, 120, 150... The multiples of 15 are 15, 30, 45, 60, 75, 90, 105, 120, 135... The common multiples of 20, 30, and 15 are 60, 120, 180, 240...
60 and all its multiples
60
60
60
LCD= 60
The multiples of 12 are 12, 24, 36, 48, 60... The multiples of 15 are 15, 30, 45, 60... 60 is the LCM of 12 and 15 because it is the first common multiple of these two numbers.
The common multiples of 12 and 15 include 60, 120, 180, 240, 300, 360, 420, 480, 540, 600, 660, and an infinite number of others. They are the multiples of 60, which is the least common multiple of 12 and 15.
The common multiples of 2, 4, 5, 10, and 15 are the multiples of the set's LCM, which is 60. Therefore, the common multiples of 2, 4, 5, 10, and 15 are 60, 120, 180, 240, 300, 360, and so on. There is an infinite number of common multiples for 2 5 10 4 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 2 5 10 4 and 15 is 60.