What is the least common multiple of 51015?
As presented in the question it looks like a single number
51015.
The lowest common multiple of 51015 depends upon the other
number(s) with which 51015 has common multiples, but it will always
be one of the multiples of 51015, namely: 51015, 102030, 153045,
204060, 255075, 306090, ...
However, I suspect that you wrote the question separating 5 10
and 15 by commas with no spaces following the commas (ie
``...multiple of 5,10,15'') - unfortunately due to limitations some
punctuation (the comma being one of them) get stripped from
questions.
The lowest common multiple of 5, 10 and 15 is 30.