How do you calculate %xHKO?

I solved this problem exactly on Pari. I have the pari program but it's still not quite intuitive enough to use. I'll be re-writing the code to try to make it more intuitive. Once it's done though, other people would need Pari (which is free) to make any use of it though T.T

Due to projects I'm hoping I'll have it done by the weekend. Seems like it'll be mostly useless for the calculator though since you'd need a supplemental but quite small program.