Coding–Decoding • Topic 3 of 4

Substitution Coding

Substitution coding replaces real words with other words ('if sky is called sea, sea is called river …') and asks 'what do we call X?'. Track the chain carefully and answer with the substituted word, not the real-world word.

Answer with the substitute, not the real word

Read "A is called B" as A → B. To answer, first find what thing the question really refers to, then give its substitute.

Example: "If red is called blue, and blue is called green, what is the colour of the clear sky?" The sky is really blue; blue is called green; so the answer is green.

The whole trap is that the obvious real-world word (here "blue") is wrong — you must give the substituted name. Underline the real thing first, then swap.

✅ Solved examples

1. If 'red' is called 'blue', 'blue' is called 'green', what is the colour of the clear sky?
The sky is really blue; blue is called 'green'. Answer: green.
2. If 'pen' is called 'pencil', what do you write an exam with?
You write with a pen, which is called 'pencil'. Answer: pencil.
3. If 'water' is called 'food', what do we drink?
We drink water, called 'food'. Answer: food.
4. If 'dog' is called 'cat', which animal barks?
A dog barks; dog is called 'cat'. Answer: cat.

✏️ Practice — try these, take hints as needed

1. If 'apple' is called 'orange', which fruit is red and crunchy?
Really an apple.
Apple is called orange.
—
orange
2. If 'car' is called 'bus', what do you drive on a highway?
A car.
—
—
bus
3. If 'green' is called 'yellow', what is the colour of grass?
Grass is green.
—
—
yellow
4. If 'book' is called 'copy', what do you read?
A book.
—
—
copy
5. If 'milk' is called 'tea', what does a cow give?
Milk.
—
—
tea

📝 Topic test — 8 questions

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