Answering the narrow version, because the broad one does not have a single answer. Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the correction. That is slower than asserting, and it is the only version that survives being wrong.

That is the short version; the long version is somebody else's post.

DanielChem_CHI said:

Whatever the answer turns out to be, the method for getting there is the same: state the assumption, do the arithmetic in public, and invite the…

Right, and the exception is worth naming rather than left implied, because the exception is where people get into trouble.

nick_newbie said:

I have used three payment routes and the only thing that changed with each was how much leverage I had when something went wrong.

This matches mine closely enough to be worth saying so out loud.

From the other side of the consultation, briefly. Worth answering the question that was asked rather than the one behind it. The narrow version usually has an answer; the broad version usually does not, and answering the broad one is how a thread stops being useful.