Study guide: Coding and Decoding Reasoning

📋 Course Outline

1. Coding and Decoding Fundamentals
2. Coding Question Types
3. Substitution Coding
4. Chinese Coding by Word Overlap
5. Number-Based Coding
6. Alphabet-Based Coding

📖 1. Coding and Decoding Fundamentals

🔑 Key Concepts & Definitions

• Coding: Encrypts words and numbers into codes by applying specific patterns and rules.
• Decoding: Decrypts coded patterns into their original forms.

📝 Essential Points

• The notes identify numerical values assigned to the alphabet as a major concept in coding-decoding questions.

💡 Memory Hook

Coding encrypts; decoding decrypts back to the original.

📖 2. Coding Question Types

★ Must-know

• The four question types are:
  • substitution coding
  • Chinese coding
  • number coding
  • alphabet coding

Further detail

• The notes describe the topic's difficulty as Easy+/Moderate.

📖 3. Substitution Coding

📝 Essential Points

• In the substitution example, the color names are successively relabeled as Reds → Blues → Whites → Yellows → Oranges → Pinks; therefore, the sky's coded color is Blue.

📖 4. Chinese Coding by Word Overlap

★ Must-know

• In Chinese coding questions, compare phrases that share words and use their shared code tokens to identify the code for a target word.

Further detail

• For 'GO WENT GONE' = 'DA MA DOF' and 'HE HAD GONE' = 'GA DOL MA', the shared word GONE corresponds to MA, leaving HAD coded as DOL.

• For 'THE LIGHTHOUSE' = 'ZU CHI PIN', 'HOUSE IS BIG' = 'MO TIM ZU', and 'THE BIG GARDEN' = 'RIZ TIM PIN', the code for LIGHT is CHI.

💡 Memory Hook

Compare the first and second phrases, then the second and third, to isolate the shared word’s code.

📖 5. Number-Based Coding

★ Must-know

• The notes map alphabet letters to their positions, including A=1, B=2, C=3, D=4, E=5, F=6, G=7, H=8, I=9, J=10, K=11, L=12, M=13, N=14, O=15, P=16, Q=17, R=18, S=19, T=20, U=21, V=22, W=23, X=24, Y=25, and Z=26.

Further detail

• In one number-coding example, SOIL is coded as 38301824, and the task is to find the code for DECIMAL.

• In another number-coding example, E=5 and HOTEL=12 are given as clues for finding the code of LAMB.

📖 6. Alphabet-Based Coding

★ Must-know

• The alphabet-coding examples ask students to infer transformations from COMPUTER → RCOW, MONKEY → ZFLOPN, DOG → FMI, and MISSIONS → MSIISNOS, then apply the patterns to other words.

Further detail

• In a previous-year question, JUNE is coded as PQRS and AUGUST as WQFQMN, and the task is to find the code for GUEST.