Concept 4 of 7
Substitution Chain: If X is Called Y…
Today's big idea
Answer the question honestly first, then rename that answer using the rules.
Your honest answer comes first, then the matching rule renames it.
How it works
👀 What's going on?
Some questions rename everyday words before asking you anything at all. 'If red is called blue...' The trap is starting with the renaming instead of starting with the question.
💡 Here's the trick
Look at the two steps above. First answer the question honestly: the sky is blue. Only then look up what blue has been renamed to, which is green. So green is the answer. Doing those two steps the other way round is where nearly everyone comes unstuck.
🪄 How to do it
- 1.Answer the question normally, ignoring every rule, as step 1 does in the picture above.
- 2.Find the one rule that renames your honest answer.
- 3.Give that new name as your final answer.
✍️ Try it
If water is called food, food is called tree, and tree is called sky, what would you drink?
You really drink water, so settle that first. The rules say water is called food, so the answer you write down is food. Notice you never needed the tree rule or the sky rule at all.
⚠️ Watch out
You might be thinking every rule in the list has to get used. Most of them are there purely to distract you. Find your honest answer first, then reach for the single rule that renames it.
🌟 Why this matters
Following instructions in the right order, rather than the order they happen to be written in, is the real skill here. A recipe or a set of directions asks for exactly the same care.
Exam tip: Underline your honest answer before you touch the rules, so the renaming cannot pull you off course.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“If pen is called pencil, pencil is called eraser, eraser is called pen — what do you write with?”
- 1
Answer normally first
You write with a pen. Ignore the rules for this step.
- 2
Check the rules for 'pen'
Rule says pen is called pencil. So swap.
- 3
Apply the swap
pen → pencil
- 4
Answer ✓
Write with = pencil
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
First answer the question for real, then swap your answer using the rules.
SUBSTITUTION · ROUND 1 OF 3
Which fruit is red and crunchy?
Step 1 — really, what is the answer?
Quick check
✅ VERIFICATION
If chair is called table, table is called bed, and bed is called sofa, what do you sit on?
⚡ Finish the activity above first to answer.
Keep going!
Up next: Letter Arrangement
Fruit / animal / colour narrows to just one real answer.