Question 475241
Made a little investigation...
Students CAN view the 50 most recent unsolved problems, even if they are not registered on the site.  (They can't view the most recent 100 up to the most recent 400 problems, though.  They have to register then.)  Students can also post questions WITHOUT registering, but won't be able to see solutions to their problems if some tutor picked up their problem and they didn't register.  So the recurring advice is valid, and should serve as a reminder for prospective students.