We dealt with this problem in school, and the reason it was thought to have no answer was because it would need a "perfect situation" for the numbers to make any sense. I hate to break it to the kid, but the math behind this problem was solved at Stanford University in a class I attended, but it was merely a side theory thrown out to show how simple equations can be disproven when impacted by "the real world." Within a vacuum, the math is of an elementary level - force of gravity, air resistance, angle, force, etc, etc. BUT, in the real world, dealing with cross winds, air pockets, humidity, heat, cold, etc, etc, etc, ETC! There is no specific mathematical equation that takes all of that into account, because a single shot taken a fraction of a second later out of the same rifle, without being moved, is still being impacted differently by nature.
It's a great theory, that I'm sure works when thrown up on a board in a stuffy classroom, it certainly did at Stanford, but the real world implications are next to worthless. Ask any 1000 yard sharpshooter if the knowledge of this equation means they no longer have to take up the second wind readings into account when competing in that bullseye competition.
Smart kid though, no two ways about it.
