There are three rules of solving the quant problems
Rule-1: Know your basics first. These are formulae, properties and almost everything of the math world. Number theory, exponents, algebra that include sequences and some word problems like principal and interest, percentages, some parts of statistical analysis etc are built around these.
Rule-2: Know how to derive an equation from sentences. Most word problems like mixtures, work-rate, distance and time, taps and flowing water problems are built around these.
Rule-3: Know what you should do with the basics to derive an equation. This is the essential part. This best works for tougher geometry, permutations and combinatorics, probability, complex sequence problems. If you can't think in the right direction to be able to derive the required equation, first thing you'll start to panic and second, you'll lose focus on thinking differently. Learn to take a moment and keep control from panicking.
As to geometry, try manhattan quant, you might find some tough questions.