Give the step-by-step reasoning process and then the final answer. Louise is hanging 30 of her pictures on the wall. She hangs some of them vertically, half of them horizontally, then hangs the remaining 5 pictures haphazardly. How many pictures did Louise hang vertically?
There are 30 / 2 = 15 pictures hanging horizontally. So there is a total of 15 + 5 = 20 pictures hanging either horizontally or haphazardly. Therefore, there are 30 20 = 10 pictures hanging vertically.
The final answer: 10.