The example you gave is not so terrible, as far as questions on Stack Overflow are concerned.
It isn't a simple typo or missing enough detail for an answer to be given. Sure, if you are seasoned enough you can answer it easily, but that doesn't make it a bad or terrible question.
So... in this example, the OP deserves a good answer.
However: for truly bad questions - actual typo issues. A comment can direct the OP in the right direction. At this point, downvoting and voting to close are fine, as such a question is not likely to be helpful to others.
There isn't much one can do when others jump in with answers - the hope is that the question will get deleted and any gained reputation will be lost, hopefully as a lesson to not answer such questions (I know it took a good few of these before I figured it out...).