Since a short time ago, I refuse to try solving math questions of which there is no solution available, unless I'm working on an own/open problem in my thesis. In subjects however, I refuse, because it is frustrating to get stuck for days and knowing that a solution exists. So knowing that I miss some important way of thinking.
Now you might think Why? If you can't solve it, just look at the course material and if that doesn't help then ask the teacher. Yes I tried that. By both mouth and mail. Unfortunately a lot of them don't like to get disturbed by students, because they are actually not real teachers, but very busy researchers who hardly have time for anything else. I also tried google, mathstack and asking students, but without a solution book it seems like it is always possible that nothing helps and you thus stay where you are: stuck.
Having said this, is there a way to learn without solution books but with the guarantee that you can always get access to the solution for the problem you work on? Maybe I do something wrong with the ways already tried?