Brain Teasers & Mental Math
Estimate (Fermi): how many ping-pong balls fit in a typical office conference room?
Model answer
On the order of 1 million (roughly ~0.9–1.4 million for a mid-size room).
Approach: assume the room is ~6m × 5m × 3m = 90 m³ = 90,000,000 cm³. A ping-pong ball is 4 cm diameter; its sphere volume is…
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