# Probability

## 15 Probability

#### PROBABILITY

Experiment: Any activity or trial performed is an experiment.

e.g. 1) Tossing of coin

2) Rolling of dice

3) Falling of rain

·      Outcomes: The results of the activity are called outcomes.

e. g. out comes for above experiments are

2)

3) It will rain, It will not rain.

·      Probability of happening of event

If total no. of trials = n

If no. of times event $\text{E}$ occurred

Then

·      Probability always lies between $\text{0}$ and v.

·      $\text{0}\le \text{p}\left(\text{E}\right)\le \text{1}$

·      If are the possible outcomes of an experiments, then sum of probabilities of each event is $\text{1}$.

i.e

e.g.

For an experiment rolling a dice

The possible out comes = Numbers - So let event ${\text{E}}_{\text{1}}\text{=}$ getting $\text{1}$ on die, ${\text{E}}_{2}\text{=}$ getting 2 on die and so on.

Then