lcm

To get the Least Common Multiple (LCM) of 15 and 60 we need to factor each value first and then we choose all the factors which appear in any column and multiply them: 

15:       35

60:    2235

-------------------

LCM: 2235

The Least Common Multiple (LCM) is:   2 x 2 x 3 x 5 = 60

Not quite Hayley    

lcm of 15 and 60

Multiples of 15 are   15,30,45,60,75,.....

Multiples of 60 are   60,120,180,......

multiples are the ones in both lists and the lowest commone multiple is the smallest on in both lists.

SO

the LCM of 15 and 60 is   [drumroll]     60