# Probability Tricks , Notes & Questions

Contents

## Probability Notes & Questions

Here is a quick Guide for those who are preparing for an IBPS bank or other exams for “Probability”. This is the important topic in IBPS Clerk exam and IBPS PO exam. You will get Tricks & Tips with proper examples.Also, these Study Notes can be downloaded in PDF format.For getting good score in IBPS exam result then read the notes onÂ probability questions.

### What is probability

Probability is one of the important chapter for IBPS bank and other competitive exams like CAT.Most of the time set of 4-5 questions is asked in competitive exams which can be solved in minutes. A mathematical measure of uncertainty is known as probability.

### Random Experiment

An experiment in which all possible outcomes are known and the exact outcome can be not be determined is called a random experiment.

### Sample Space

Set of all possible results of a random experiment is known as sample space.

Also Read:  Important Computer Abbreviations for IBPS Clerk & PO

### Trial

The performance of a random experiment is called a trial.

### Event

It is a subset of sample space.

### Probability of occurrence of an event

Let S be the sample space and E be the event then E$\quad \subseteq \quad$ S.

$\therefore \quad P\left( E \right) =\frac { n(E) }{ n(S) }$

Question 1:Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5?

Question 2:A boy gets a chance of 55% to win 1st round of a game and a girl gets a chance of 60% to win 2nd round of the game. In what % of cases are they likely to contradict each other, narrating the same incident?

Question 3: In a class, there are 12 boys and 16 girls. One of them is called out by an enroll number, what is the probability that the one called is a girl?

Question 4:A box contains 6 bottles of variety1 drink, 3 bottles of variety2 drink and 4 bottles of variety3 drink. Three bottles of them are drawn at random, what is the probability that the three are not of the same variety?