Classification
Classification is the process of classifying an object, word, letter or number into a group on the basis of their common properties, shape-type, appearance, color, character and other properties.
In questions based on classification, some words or letters or numbers are given, except one of them, other words or letters or numbers are similar to each other in a particular way, and they form a group of their own. One of them differs from this group. You have to find that different word or letter or number.
For example, if we compare the elements like, lion, cow, tiger, panther, bear and wolf then we find that this is a group of animals. How do we classify them?
Here, if we want to separate out one animal then definitely that animal will be the cow because cow is the only animal in the group which is a domestic animal. The rest of the animals (Lion, Tiger, Panther, Bear and Wolf) are wild animals and form a group of wild animals.
Types of Classification
Type 1. Word Classification
In this type of classification, different objects are classified on the basis of common features/properties – names, places, uses, situations, origin, etc.
Example 1: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- Work : Leisure
- Day : Night
- Expedite : Procrastinate
- Frequently : Always
- Happy : Unhappy
Solution. (4): All others are the antonym of each other.
Example 2: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- March
- January
- July
- June
- May
Solution. (4): All other months have 31 days while June has 30 days.
Type 2. Alphabet Classification
In this type, the alphabet is classified in a group using particular methods or rules. These rules or methods are often simple and hence can easily be understood.
Example 3: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- BY
- LO
- EW
- GT
- SH
Solution. (3): All others letter pairs are the combination of opposite places in the alphabet.
Type 3. Number Classification
In this type, numbers are classification in a group using a particular method or rule. Rules or methods used for such classification may be based on mathematical operations.
Example 4: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- 25—5
- 16—4
- 144—12
- 64—7
- 36—6
Solution. (4): In all other number pairs, the first number is the square of the second number.
25 = 5², 16 = 4², 144 = 12², 64 ≠ 7², 36 = 6²
Example 5: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- 63
- 42
- 35
- 21
- 65
Solution. (5): All other numbers are divisible by 7 while 65 is not divisible by 7.
Type 4. Number and Letter Classification
In this type of classification, the combination of alphabet and number is classified in a group using particular methods or rules.
Example 6: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- 25—E
- 16—D
- 144—L
- 64—G
- 36—F
Solution. (4): In all other number-letter pairs, the number on the left side is the square of the position of the letter on the right side.
- 25 = 5², (The position number of the letter E is 5)
- 16 = 4², (The position number of the letter D is 4)
- 144 = 12², (The position number of the letter L is 12)
- 64 ≠ 7², (The position number of the letter G is 7)
- 36 = 6², (The position number of the letter F is 6)
Type 5. Miscellaneous Classification
In this type of classification, any rule other than described above can be used for classification or grouping. Questions on such patterns do not necessarily use alphabets and words. Here the numerics and other mathematical symbols can also be used.
Example 7: Four of the following five are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- –
- +
- %
- =
- ÷
Solution. (3): All others represent mathematical operations.
Example 8: In each of the following five options each has a combination of three words group. In which, four groups are alike in a certain way and so form a group. Which is the one that does not belong to that group?
- Driver, passenger, vehicle
- Chair, table, bench
- Ship, boat, pilot
- Apple, orange, winter
- Mango, flower, orchard
Solution. (2): Chair, table and bench belong to a category of furniture.
Solved Examples
Example 9. Which one is different from the rest three?
- Door
- Gate
- Table
- Window
Solution. (3): All the rest are the parts of a building.
Example 10. In this question, there are four words with the letters jumbled up. Three of them are alike. Find the odd one out.
- CIRE
- NAIR
- LOUDSC
- RNUTHDE
Solution. (1): By arranging the letters of NAIR, LOUDSC and RNUTHDE we get RAIN, CLOUDS and THUNDER respectively which are all related to one other except CIRE i.e., RICE.
Example 11. Which one is different from the rest three?
- NMLK
- RQPO
- UTSR
- WXUV
Solution. (4): In all the other options, the letters are in the reverse order of the alphabet.
Example 12. Which one letter group differs from the other three?
- WRONG
- GREEN
- WHITE
- RIGHT
Solution. (2): In other options, no letter is repeated.
Example 13. Three of the following are alike in a certain way and form a group. Find the odd one out.
- Bird
- Insect
- Aeroplane
- Kite
Solution. (2): All except the insect fly in the sky.
Example 14. Find the odd one out.
- 28
- 14
- 49
- 64
Solution. (4): Except 64, all the rest numbers 28, 14 and 49 are divisible by 7 while 64 is not divisible by 7. Therefore 64 is different from the rest.