Find the smallest four digit number which is divisible by $15,25,40$ and $75$ I'm stuck on this question. My working:
\begin{align*}
15 & = 3 \cdot 5\\
25 & = 5^2\\
40 & = 2^3 \cdot 5\\
75 & = 3 \cdot  5^2
\end{align*}
LCM $= 600$
And I'm not sure what to do after this (if the above steps are right). 

LCM of $15,25, 40 , 75$
will be $600$
The smallest $4$ digit number is $1000$;
Now find the multiple of $600$ close to $1000$.
Hence it's answer is $1200$
