Answer & explanation
The official answer, with Fermi’s reasoning step by step.
Answer & explanation
Official answer
21
Icelands
How to estimate it
Fermi’s official “Napkin math”
Greenland runs about 2,500 kilometers top to bottom and 1,000 across, and it tapers at both ends. Call it 2 million square kilometers. How big is Iceland? A rounder island roughly 300 kilometers wide, so about 100,000.
- Greenland
- ~2,000,000 km²
- Iceland
- ÷ 100,000 km²
- 2,000,000 ÷ 100,000
- ≈ 20
Greenland runs about 1,600 miles top to bottom and 600 across, and it tapers at both ends. Call it 800,000 square miles. How big is Iceland? A rounder island roughly 200 miles wide, so about 40,000.
- Greenland
- ~800,000 sq mi
- Iceland
- ÷ 40,000 sq mi
- 800,000 ÷ 40,000
- ≈ 20
Rounded assumptions may give a slightly different estimate. The official answer above is the game’s reference value.
Source calculation & reference
- Greenland area
- 2,166,086 km² (836,300 sq mi)
- Iceland area
- 103,000 km² (39,800 sq mi)
- 2,166,086 ÷ 103,000
- ≈ 21
Reference cited by Fermi: CIA World Factbook (Greenland, 2,166,086 km²; Iceland, 103,000 km²)
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