Bob already pointed them in the right direction without basically spelling it out for them, which apparently wasn't enough for the OP, hence my suggestion that maybe he/she will want to consider a degree change if a relatively simple question is tripping them up. It was clearly more than enough for you to find the information, so everything the OP needed was right there in front of them.
As I said, it's not about knowing everything immediately off the top of your head, but knowing how to find the information. Nothing wrong with a general hint to get you started, after all that's essentially what you're doing when you take a similar solution and adapt it to a different set of circumstances. There's a big difference between that, however, and serving up the answer directly like you did. Especially in an academic setting where that kind of thing is generally considered cheating and all you're teaching the OP how to do is rely on others for the answers to everything. It sounds harsh, but maybe they should fail this exam and/or class because they do not seem to have a firm grasp on the material.
There's no shame in that as far as I'm concerned. They don't just have flunk out classes in colleges out of some kind of sadistic desire to see people fail, they are there to try and force people to reevaluate whether or not this is the right degree for them. If someone is struggling with the relatively simple aspects that will form the foundation of knowledge you need going forward, are you really doing this person any favors giving them the answer? Would you bet your life on crossing a bridge designed by a civil engineer who only passed the math classes by getting the answers from someone else? Or how about be operated on by a surgeon who can't remember the different parts of the circulatory system? Granted computers are rarely a life or death proposition, but the principle stands.
Plus, there's the economics of a degree. Degrees only mean something if there's a level of scarcity in who can obtain them. If every Tom, **** and Harry can get a PhD in Nuclear Physics, whether or not they even know what an atom is, how doesn't the value of that degree go to zero? If you've got to hire someone and have 500 applicants, do you have the time or inclination to try and weed out the ones who actually might know what you need from the ones who don't know jack? No, you're just going to toss every application from someone who graduated from that college in the trash and look for a school that only gives out degrees to people who have earned them. Up until the Ivy League schools started letting rich alumni buy admission, grades, and basically whole degrees, the reason those degrees held so much prestige is because those schools were extremely selective in everything from admissions to graduation. If you made it all the way through to get a degree from Harvard or Yale, that meant you were among the best of the best. Now of course it's just a good-old-boys crony institution designed to prop up the nepotism common in large institutions and you see the associated erosion of the prestige that goes with having a degree from those schools. So you have other institutions across the country, or world even, which are known for a particular program. Usually they're known for pumping out quality graduates because it's difficult to get in, the work load is grueling, and there is a high attrition rate among those who do get in.