well lets think of the first number that can fit 12, well 60 works right?? 12 fits in 60 5 times does it work with 15, yes it does, 15 fits in 60 4 times, but is that our smallest number lets check it our lets ssubtract 12 from 60, it is 48 is there a number that multioplied by 15 that can give you 48?? NO!! lets subtract 12 more this gives u 36 can something fit? NO! lets take 12 more and get 24 does anything multiplied by 15 give you 24?? No! so our smallest number would be 60 because nothing else can work for both of this nubers
Hope this helps
