First approach, Strongest subject followed by the weakest subject followed by the subject you're moderate at, has multiple benefits. You should solve your strongest section as it will give your morale support and you can solve large number of questions.
Second approach, Chemistry is a subject that has the highest scoring capacity even if it is one's weakest subject. It's a time saver for most of us as it requires the least amount of computations and the answers are usually binary in nature: you either know it correct or don't know it. No middle way and hence no wastage of time otherwise. This gives you time for computational problems in Maths and Physics. After Chemistry, go for the subject which is weaker among Maths and Physics.
You can try both sequence and decide which one is better for you.