The Puzzle in the Image
A handwritten “Harvard University Interview” riddle asks:

• “7 men have 7 wives.”
• “Each man and each wife have 7 children.”
• Question: What’s the total number of people?
  The “90% were eliminated” line is there for drama, but it doesn’t affect the math.

The Key to Solving It: One Ambiguous Sentence
Everything depends on how you interpret this line: “7 men have 7 wives.”
It can mean either:

• Interpretation A (shared total): The group of 7 men has 7 wives total (most naturally read as 7 couples).
• Interpretation B (per man): Each of the 7 men has 7 wives (which would be 49 wives total).

Solution A (Most Common Reading): 7 Couples
If 7 men have 7 wives total, you have 7 married pairs.

1. Adults: 7 men + 7 wives = 14 adults
2. Children: If each man and each wife have 7 children together as a couple, then:
   • 7 couples × 7 children each = 49 children
3. Total people: 14 adults + 49 children = 63 people

Result: 63

Solution B (If Each Man Has 7 Wives): A Much Larger Family Tree
If each man has 7 wives, then:

1. Wives: 7 men × 7 wives each = 49 wives
2. Children: Each man–wife pairing has 7 children, so:
   • 49 pairings × 7 children = 343 children
3. Total people: 7 men + 49 wives + 343 children = 399 people

Result: 399

Which Answer Is “Right”?
In logic riddles, the “correct” answer is usually the one supported by the exact wording.

• The image does not say: “Each man has 7 wives.”
• It says: “7 men have 7 wives.”
  That wording most strongly implies 7 wives total, leading to 63.

Takeaway: The Real Test Isn’t Math, It’s Reading Precision
This puzzle is designed to trigger a fast assumption (“polygamy”) and reward careful reading.

• If you read it as a group total, the answer is 63.
• If you rewrite it as each man has 7 wives, the answer becomes 399.