# SSC Exam Quantitative Aptitude Study Material: A conceptual guide for Combination

Jun 22, 2016 12:42 IST

SSC is well known for the recruitment of Group ‘B’ and ‘C’ posts under the Ministries/Departments in The Government of India. SSC organizes various examinations like Combined Graduate Level examination, Combine Higher Secondary Level, Stenographer and for SI/DP/CAPF, etc., throughout the year having almost the same Exam Pattern. The Exam paper is comprised of basically 4 subjects.

a. General Intelligence & Reasoning

b. English language & Comprehension

c. Quantitative Aptitude

d. General knowledge

For more detail, click the link given below.

SSC SI, CAPF & ASI Exam 2015: Exam Pattern

SSC Combined Higher Secondary Level (10+2) Exam 2014: Exam Pattern

SSC JHT & Hindi Pradhyapak and Sr. / Jr. Translators Exam 2014: Exam Scheme & Syllabus

SSC Stenographer 2016: Take a look of Exam Pattern, Syllabus and Selection Procedure

So, Jagranjosh.com has introduced a brief plan for revising topics at the time of examination. In this article, Combination which sometimes appear more difficult to understand in terms of making combinations & collections.

Combination

From a given group of object each of the number of groups which are formed by taking some objects or all objects at a time without caring about the sequence of the objects is called combination. The number of combination formed by taking r objects at a time out of n object is denoted by nCr where C expresses combination.

Restricted combination:

The combination of r object out of n objects on which p specific objects:

1. Are always included is n-pCr-p. We have to keep aside p specific objects and to select remaining (n-p).
2. Are never included is n-pCr . Since p specific object are never included we have to form the combination taking r obects out of (n-p) objects.

The number of ways to select some or all thing out of any number of given thing:

There are 2 ways to select anything i.e. either it will be selected or not. Therefore number of ways to select n things is 2 × 2 × …………… n times = . 2n these empty selection is also include. For non- empty selection is 2n-1.

Note: nC1 + nC2 +…………………………. + nCn = 2n-1.

Difference between permutation and combination:

Suppose there are 5 objects out of which 2 have to be chosen.

So it is clear that in permutation order matters while in combination order does not matter.

## Register to get FREE updates

All Fields Mandatory
• (Ex:9123456789)
• Please Select Your Interest
• Please specify

• A verifcation code has been sent to
your mobile number

Please enter the verification code below

Newsletter Signup
Follow us on
This website uses cookie or similar technologies, to enhance your browsing experience and provide personalised recommendations. By continuing to use our website, you agree to our Privacy Policy and Cookie Policy. OK
X