WTFingF is with some people?!
Everybody knows that geeks and nerds tend to have lower social skills, but this sort of pointless and repeated flaming is just ridiculous.
Re the question and the matter of answering it, I'd agree with HiTech here: it's not just doing the maths but having a decent sense of how to apply it. I think that sort of thing comes with practice, and when you're new it's easy to slip up.
Tronicbrain: You saw that the actual
resistance value was correct at least, the problem was just that R4 will dissipate more power than it is rated for. HOWEVER, you could replace R4 with 4 resistors of the same type: 2 in series, in parallel with
another 2 in series. That set of resistors would have the same total resistance (50
hm: ), but could dissipate 4x as much power. (unless I'm more sleep-deprived than I realise!)
So anyway, you
could make this whole 30
hm: network of resistors you're describing with 7 instead of 4 (I presume you understand how), and it would AFAICT be ok. Whether or not it's worth the bother and circuit space is up to you
Perhaps it's a hypothetical question instead of a practical one though.