This solution got me thinking about something which I found interesting enough to feel the need to share. I can imagine my Dad using this geometric method to s

This solution got me thinking about something which I found interesting enough to feel the need to share. I can imagine my Dad using this geometric method to solve the problem at hand. He's a very intelligent guy who has worked in the building industry doing manual labor all of his life. I can guess that my sister, who is a medical doctor, would have solved it using the same process as the (current) top rated response here; stepping through the equations. My immediate response would be to hack up a script and brute force the answer. My Mother would tell me to go ask Dad.