Tricks, Tips & Shortcuts in Number Ranking

Part-2 (Reasoning Section)

Introduction:

This article covers the topic of Number & Ranking questions based on which are asked under the reasoning section in various competitive exams like IBPS Clerk, SBI Clerk, SSC CGL, Placement Aptitude, IBPS PO, SBI PO, NICL AO, LIC  AAO, SBI Associate Clerk, SBI Associate PO, CAT and others. There are usually 3-5 questions in any exam from this topic. By following some simple shortcut tricks, you can easily crack the questions in a matter of seconds.

To Read Part 1 : Click Here

 


Number Ranking :TYPE 5

Positions of two persons is given and their positions are interchanged and after interchanging position of 1st person is given from same side as before interchanging

Position of 2nd person from the same side as before interchanging = Position of 2nd person from same side before interchanging + (Position of 1st person after interchanging – position of 1st person before interchanging from same side)

To find total no. of students Þ Find the person whose position from both sides can be depicted from the statement. Add both his positions from opposite ends and subtract 1.

To find no. of persons between them Þ Difference in the position of common person whose position from same side before and after interchanging is given then subtract 1

E.g. A and B are standing in a row of persons. A is 18th from left side of the row and B is 24th from right side of the row. If they interchange their positions A becomes 31st from left. Find

i) New position of B from right side

ii) Total no. of persons

iii) No. of persons between A & B

Explanation:

i) New position of B from right side = Position of B from right side before interchanging + (Position of A from left side after interchanging – Position of A from left side before interchanging)

⇒ New position of B from right side = 24 + (31 – 18) = 24 + 13 = 37th

ii) Total no. of persons = (A’s position from right before interchanging + A’s position from left before interchanging) – 1

⇒ Total no. of persons = (B’s position from right after interchanging + A’s position from left before interchanging) – 1

⇒ Total no. of persons = (24 + 31) – 1 = 55 – 1 = 54

iii) No. of persons between A & B = (Position of A from left after interchanging– Position of A from left before interchanging) – 1

⇒ No. of persons between A & B = (31 – 18) – 1 = 13 – 1 = 12


Number Ranking :TYPE 6

If positions of two different persons are given from opposite sides of the row and a third person is sitting exactly in middle of the two and total no. of persons in the row is to be calculated as

  1. i) When position of third person sitting is given from either side of row
  2. ii) When position of third person is given from either of the two persons between whom he/she is sitting

Then find the position of the 3rd person from both sides of the row and hence find total no. of persons according to type 1

E.g. 1) In a row of persons, position of A from left side of the row is 9th & position of B from right side of the row is 8th.If C is sitting just in middle of A & B and position of C from left side of the row is 15th. Find the total no. of persons in the row?

Explanation:

Position of C from left is 15th and A from left is 9th so there are (15 – 9 – 1 = 5) persons are sitting between A and C. As C is sitting in middle of A and B so there must also be 5 persons sitting between B and C.

Thus position of C from right = Position of B from right + 5 + 1 = 8 + 6 = 14th

Total no. of students = (Sum of positions of C from both sides – 1)

⇒ Total no. of students = (15 + 14) – 1 = 29 – 1 = 28


E.g. 2) In a row of persons, Position of A from left side of the row is 11th and B from right side of the row is 19th. If C is sitting just in middle of A & B and position of C from A is 7th. Find total no. of persons in the row?

Explanation:

Position of C from Left = Position of A from left + Position of C from A = 11 + 7 = 18th

Given C is 7th from A and C is sitting in middle of A and B then also C is at 7th position from B

Position of C from right = Position of B from right + Position of C from B = 19 + 7 = 26th

Total no. of students = (Sum of position of C from both sides – 1)

⇒ Total no. of students = (18 + 26) – 1 = 44 – 1 = 43


Number Ranking :TYPE 7

In the questions where it is asked to find minimum no. of persons in a row then it is always a case of overlapping i.e. given positions of persons from either sides overlap each other.

Then

Minimum no. of persons = Sum of positions of persons from both sides – Persons between them – 2


E.g. If position of A from left side of a row is 15th and position of B from right side of a row is 19th and only 1 person is sitting in middle of A & B. Find the minimum number of persons that can be seated in this row?

Explanation:

Total no. of persons = 15 + 19 – 1 – 2 = 31


Number Ranking :TYPE 8

These are numbering type questions. In this type of question, it is given that there are several people living in an n-storey building. Some information will be given about the relative positions of one above or below the other. You need to find which floor each person lives on. These are almost similar to seating arrangement questions. However, you may be required to apply the rules you learnt above, in these problems.

Ranking And Direction Short Cut:

RANKING TEST:

In this type, generally a set, group or series of numerals is given and the candidates is asked to trace out numerals following certain given conditions or lying at specific mentioned positions after shuffling according to a certain given pattern.

Examples:

Here is a table.

No. Rank from top Rank from bottom
A           1                       6
B           2                       5
C           3                       4
D           4                       3
E           5                       2
F           6                       1

 

Let discuss about ‘D’

D’s rank from top = 4 and from bottom = 3

Now total rank = 6

Means total rank = (rank from top + rank from bottom) – 1

Now rank from top = (total rank + 1) – rank from both

Rank from bottom = (total rank + 1) – rank from top


Up Next: Blood Relations (Published Soon)


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