There is task fragment:
"However, you must round the result in such a way, that it is accurate to 8 inches (1 foot is equal to 12 inches)"

I thought it means that result should be int and (result*12) should be divided by 8 without reminder. I received WA3.

When I ignored requirement and used simple rounding like int(result+0.5) I got ac.

So, does requirement mean anything? Maybe it should be removed from task?