For integers x and y, 2^x + 2^y = 2^(36). What is the value of x + y? Think about …

## To use permutation or combination formula?

A recurring question from many students who are preparing for CAT is this: When should one use the permutation formula and …

## Keeping an open mind in CR

Let’s take a look at an example. All of the athletes who will win a medal in competition have spent …

## Driving Rules for Sentence Correction

When driving in the snow: Don’t brake until you have to. Don’t make sudden turns or lane changes, and only …

## Logic in Algebra questions

Here’s an example: If x, y, and k are positive numbers such that [x/(x+y)]*10 + [y/(x+y)]*20 = k and if …

## Critical Reasoning involving rates

Let’s look at an question and convince you of the right answer: The faster a car is traveling, the less …

## Difficult questions using basic concepts

It may seem like we will need trigonometry to handle this question, but that is not so. In fact, the …

## Circular Arguments in Critical Reasoning

Consider this argument: Anatomical bilateral symmetry is a common trait. It follows, therefore, that it confers survival advantages on organisms. …

## Ratios in Data Sufficiency

We know that ratios are the building blocks for a lot of other concepts such as time/speed, work/rate and mixtures. …

## Interest Equations

The reason people are intimidated by the kinds of compound interest equations we encounter in finance classes is that they …