I got 823 out of 1000, which is actually better than I did on the (supposedly less difficult) 70-290.
They questions were a lot like the sample test questions in the back of the MS Press blue book for the exam, and in the ExamForce Simulated Exams. They were pretty much all scenarios (mostly "You are the network administrator of xxx's network, and..."), and gave a background story as to why you're doing the subnetting it's asking you to do. As far as I remember, there weren't any questions that were written out as plainly as the example you gave.
In once particular case, the question gave the current setup for a company's network (with the existing ISP-provided IP address blocks for its subnets), and said that due to the increase in size of one of the subnets, an extra block of addresses was added. Basically, you had to figure out which address blocks were contiguous and could be combined into a single subnet, in order to support twice as many hosts as before. The question itself wasn't really too hard, it was just a different approach to the same type of problem.
I didn't notice any "gotcha" type questions, though for all I know there may be some in the question pool somewhere. As long as you're comfortable with subnetting and take your time (of which there is plenty) to read and understand each question, you should be fine.