Let’s go step by step.
We are told a man has 9 sons, so that part is clear.
Then it says: each son has a sister.
Most people assume this means 9 different sisters, leading to:
9 sons + 9 sisters + father = 19 people ❌
But the statement never says “each has a different sister.” It only says they have a sister.
That means all 9 sons can share one sister.
So the correct count is:
- 9 sons
- 1 sister
- 1 father
Total: 11 people ✅
The trick is that your mind adds extra assumptions that aren’t actually written.