# Probability Class 11

Probability Class 11 – A experiment is said to be a random experiment if It there are more than one possible outcomes and it’s impossible to predict the outcome in advance. All possible results of an experiment are called its outcome. Let us consider an experiment of rolling a die. All possible outcomes are 6, 5, 4, 3, 2, or 1. The set of all these outcomes {6, 5, 4, 3, 2, 1} is known as the sample space (denoted by ‘S’). Let us consider an experiment of tossing Two coins once. Since either coin can turn up Tail or Head, therefore, all the possible outcomes are: Both coins – Head = HH, Both coins – Tail = TT, First coin – Head and Second coin – Tail = HT, First coin – Tail and second coin – Head = TH. Therefore, the sample space (S) can be represented as = {HT, TT, TH, HH,}. For any random experiment, Let S be the sample space. The probability P is a real valued function whose domain is the power set of S and [0,1] is the range interval.

(i) For any event E,$P (E) \geq 0$

(ii) P(S) = 1

(iii) If E and F are mutually exclusive events, then $P(E \cup F) = P(E) + P(F)$

### Probability Class 11 Examples

#### Practise This Question

Let the sequence a1,a2,a3.....an form an A.P. Then
a21a22+a23a24+.....+a22n1a22n is equal to