Lessons / Logical reasoning
Logical reasoning · Day 9

Analogy

Say the relation in one sentence ('a doctor works in a hospital') and apply the same sentence to the second pair.

Why this topic matters

Doctor is to hospital as teacher is to ? School. An analogy asks you to find the relation in the first pair and repeat it.

Word, number and letter analogies test one skill: say the relationship in a sentence, then apply the same sentence.

Say the relationship as a sentence

'A doctor works in a hospital.' Now: 'A teacher works in a school.' If the sentence fits more than one option, make it more specific.

Common relations: worker-place, tool-worker, part-whole, cause-effect, opposite, young one (dog : puppy), group (fish : shoal).

Example 1Pen : Writer :: Scalpel : ?
  1. 'A writer uses a pen.'Tool - user.
  2. A surgeon uses a scalpel.

Number and letter analogies

Numbers: look for square, cube, x 2 + 1, sum of digits. 4 : 64 :: 5 : 125 (cube).

Letters: compare positions. ACE : BDF means each letter +1.

Example 17 : 50 :: 9 : ?
  1. 72 + 1 = 50.Try squares first.
  2. 92 + 1 = 82.
Example 2CAT : DBU :: DOG : ?
  1. Each letter +1.
  2. EPH.

Formula summary

Word analogy
Worker:tool, product:raw material, part:whole, animal:young, synonym, antonym.
Number analogy
Square, cube, x2+1, digit sum. 3:27 :: 4:64 (cube).
Letter analogy
Same shift on each letter. ACE:BDF :: GIK:HJL.

Shortcuts and tricks

Number-pair check

Use it when: 3 : 10 :: 5 : ?

  1. Test n2 + 1: 9 + 1 = 10.
  2. 5 → 26.
Example3 : 10 :: 5 : ?
  1. n2 + 1.

Before you move on, you should be able to...

  • say the relation as a sentence
  • test squares and cubes for number pairs
  • compare letter positions

Practice questions (6)

Try each one before opening the solution. Or practise them one by one so your score is saved.

easy Doctor : Hospital :: Teacher : ?
  1. Where they work.

Answer: School

easy 7 : 50 :: 9 : ?
  1. n2 + 1.

Answer: 82

easy Cow : Calf :: Dog : ?
  1. Young one.

Answer: Puppy

easy ACE : BDF :: GIK : ?
  1. +1 each.

Answer: HJL

medium 11 : 1331 :: 13 : ?
  1. Cube.

Answer: 2197

medium BCD : YXW :: FGH : ?
  1. Reverse letters.

Answer: UTS

Class plan (2 hours, for trainers)

A tested order for teaching this topic in one 2-hour session. Present mode follows the same order.

10 minWarm-up.
30 minWord relations: 10 pairs, say the sentence.
25 minNumber analogies.
15 minLetter analogies.
35 minPractice set.
5 minRecap.