Some are just teasers (which are multiple-choice questions) meant to test your understanding of the subject.
Know the nature of the problem and proceed accordingly.
To get a solution, all you have to do is plug in the values of known quantities, into a related thermodynamic relation, to get an answer.
Another broad class of problems is the analytical type.
Write every step of the calculation cleanly and try to simplify it, as much as possible, at every step.
If you have gone by the right route, a solution will not elude you.
These require you to work on the given clues and set up an equation for solution.
They may require you to manipulate and solve the equations.
You can take guidance from your instructor, regarding the mathematical techniques needed.
I cannot tell you how to solve a particular problem, as there are many types.