Concept 7 of 7
Order the Steps: One of Them Does Not Belong
Today's big idea
Build the chain from what links, then test whatever card is left over.
One card is only related to the process, not a stage of it; that is the intruder.
How it works
👀 What's going on?
A Class 5 sequence question quietly adds a step that is not part of the process at all. Order the list without noticing, and you will force the intruder into a place it was never meant to have.
💡 Here's the trick
Look at the five cards above: Cocoon, Butterfly, Egg, Caterpillar, Flower. Four of them link into one chain, from egg to caterpillar to cocoon to butterfly. A flower is not a stage a butterfly passes through, so it is the intruder and the chain is only four long.
🪄 How to do it
- 1.Build the chain from whichever cards clearly link, as four of the five above do.
- 2.Try the leftover card at every point in that chain.
- 3.If it fits nowhere without breaking the links, it is the intruder rather than a step.
✍️ Try it
From Dough, Flour, Butter, Bread and Wheat, build the chain and name the intruder. Then do the same with Cloud, River, Rain, Ocean and Sand.
Wheat becomes flour, flour becomes dough and dough becomes bread, so Butter is the intruder. Ocean water rises to cloud, falls as rain and runs as a river, so Sand is the intruder.
⚠️ Watch out
You might be thinking the intruder is whichever card looks least important. It is usually the one that is related to the topic but is not a STAGE of it. Butter belongs in a kitchen and still is not a step from wheat to bread.
🌟 Why this matters
Telling a stage of a process from something merely connected to it is what makes an explanation correct rather than roughly right. It is the same care a diagram needs.
Exam tip: Count how many cards the question expects in the chain before you start ordering.
Watch me solve one
Quanta solves it
“Watch how I think through one of these — then you try.”
THE PROBLEM
“Which does NOT belong: Rain, Cloud, Umbrella, River, Sea?”
- 1
Build the chain first
Sea → cloud → rain → river links up as the water cycle.
- 2
Try the leftover everywhere
An umbrella breaks the link wherever it is inserted.
- 3
Related is not a stage
An umbrella is used in the rain, but is not a stage of the cycle.
- 4
Answer ✓
Umbrella
Now you try one — same steps, different story 👇
See it in action
⚡ Time to play!
Build the chain from what links, then test the leftover.
INTRUDER FINDER · ROUND 1 OF 3
Step 1 · how do you find the intruder?
Quick check
✅ VERIFICATION
Which step does NOT belong: Egg, Caterpillar, Flower, Cocoon, Butterfly?
⚡ Finish the activity above first to answer.
Keep going!