Important Formulas - Probability or Chance Probability or Chance Probability or chance is a common term used in day-to-day life. For example, we generally say, 'it may rain today'. This statement has a certain uncertainty. Probability is quantitative measure of the chance of occurrence of a particular event. Experiment An experiment is an operation which can produce well-defined outcomes. Random Experiment If all the possible outcomes of an experiment are known but the exact output cannot be predicted in advance, that experiment is called a random experiment. Examples Tossing of a fair coin When we toss a coin, the outcome will be either Head (H) or Tail (T) Throwing an unbiased die Die is a small cube used in games. It has six faces and each of the six faces shows a different number of dots from 1 to 6. Plural of die is dice. When a die is thrown or rolled, the outcome is the number that appears on its upper face and it is a random in...