I am a keen learner of physics, but I am unable to solve problems involving lenses and mirrors together. please can anybody tell me the method to solve these problems? for instance let us take a problem involving a convex mirror and a concave lens and we are supposed to find out the image of the object.
These kind of problems are generally solved using ray diagrams in the first instance. Any good school or undergraduate level textbook should explain these things, for example the chapter on geometric optics in "Optics" by Eugene Hecht (available online). In the future, try and include some kind of diagram or demonstration of your own attempt to solve the problem you are working on so that constructive help can be given. (I would have added this as a comment but I don't have enough rep yet). Good luck in your studies.