This is a classic riddle that plays on language rather than requiring complex math.
Let’s break down the sentence:
“A farmer had 17 sheep. All but 9 of them ran away. How many sheep does she have left?”
The key phrase is:
“All but 9 of them ran away.”
- “All but 9” means
everything except 9.
- So, if all *but* 9 ran away, that means
9 did NOT run away.
- Therefore, the 9 that didn’t run away are the ones
she still has left.
> 🐑
Answer: 9 sheep
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Why it tricks people:
Many people instinctively think:
*“She had 17, some ran away — so subtract!”*
And they might do 17 – 9 = 8 — which is wrong in this context.
But the phrase “all but 9” doesn’t mean “9 ran away” — it means “everyone except 9 ran away,” so
9 remained.
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✔ Final Answer:
9
Parent Tip: Review the logic above to help your child master the concept of science brain teasers worksheet.
