Most of the other answers focus on how programming is not typing (which I agree with, of course), but I think they miss the point. Yours answers directly and I agree with it.

Working 5 to 10 hours a week seems very low to me, though as a lead or as a coworker I would judge OP by the impact, not by the time spent behind the computer. But I doubt anyone can have serious impact in such time.

I had the chance to work with a brilliant coworker who preferred to slack off - and have passed on recommending him for this very reason.

World is a big place and there are many ways to go through life, so I'm not judging - but if you're asking if this is common, then the answer is "no, not at the places where I worked, and not how I work".

Of course you would have to pay/promise me fortune to get more than 40hr weeks from me, but I'm not hiding that. :-)