I tried to solve this problem but I was not able to. Can someone please tell me the way to solve this problem in simple ways? I have looked up for the solution to this problem on the web but I wasn't able to get a well explained answer. I am just looking for unordered pairs of solutions.
One more question related to this problem. So in this problem we have been asked to find number of pairs of $(a,b)$ such that $LCM(a,b)=200=2^3 \times 5^2$ but is there a generalized way to solve for triplets, quadruplets etc.too? Like how many triplets of $(a,b,c)$ such that $LCM(a,b,c)=200=2^3 \times 5^2$ or how many quadruplets of $(a,b,c,d)$ such that $LCM(a,b,c,d)=200=2^3 \times 5^2$