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

1 Answer

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#