The probability of an event is a number between 0 and 1 that describes the likelihood that the event will occur. Events can also be called outcomes or possibilities.
Probability can be given as a fraction (2/5), a ratio (2 in 5) or a percent (40%).
Probability is often seen as a very difficult part of the GMAT, but by logically applying one simple fraction you can make probability much easier. Start with probability in its most basic form.
You have a fair six-sided die. If you roll it once, what is the probability you roll a 5?
There are 6 sides to the die, and each is equally likely to come up. So there are 6 possible outcomes, and rolling a 5 is the one that you want. Therefore, there is a 1 in 6 probability that the 5 will come up. (Note: die is the singular of dice.)