Question

What is the LCM of 3, 5, 15, 16?

Answer 1

240

Explanation:

For LCM problems, I like to do a prime factorization first:

`3=3`
`5=5`
`15=3xx5`
`16=2xx2xx2xx2`

And now the LCM will have all the primes listed.

So - we have a 3 from the 3. We have a 5 from the 5. The 3 and 5 of the 15 are already listed, so we can move on to the 16 which has four 2s. So the LCM is:

`3xx5xx2xx2xx2xx2=15xx16=240`

`3 xx80=240`
`5xx48=240`
`15xx16=240`