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## Thursday, 7 August 2014

### CHAPTER 1 - Probability

We talk a lot about probability in our every day life, knowing or unknowingly. Each of us has some intuitive notion of this concept. For example, ponder over these statements:
 “ There is a good chance that it will rain today ” “ India is almost sure to win this $T20$ match against Pakistan ” “ The stock market is likely to fall again soon ” “ Issac Newton is probably the most influential human to have ever existed ”
We make in numerous statements of these sort everyday. There is an underlying “chance” element in each such statement. Have you ever paused and wondered why this chance element arises, and how our minds are able to quantify this chance element intuitively, without any mathematical knowledge whatsoever? If you haven’t, this chapter gives you a chance to do so!

#### MOTIVATION AND INTRODUCTION

The aim of this chapter is to make you understand how probabilities are calculated. We will, of course, use our intuition in this task as much as possible, but you’ll see in some cases that our intuition in matters of probability can be off the mark!
Let us see some examples from everyday life that’ll give you an idea of the mathematical significance of probability and the necessity of calculating exact probabilities. We will, for the time being, not worry too much about the issue of defining probability rigorously in a mathematical sense; we’ll postpone that matter to some point later in the chapter; for now, we’ll keep the discussion intuitive.