solve/quant
Quant & puzzles
Probability, bet sizing, markets and brain teasers.
Quizzes
+5% average, 87% end up downExpected value · Monte Carlo · 10,000 players
Medium
Wins 90% of trades, still down $15,000Expected value · Monte Carlo · 1,000 traders
Easy
A 60/40 coin: how much do you bet?Bet sizing · Monte Carlo · 10,000 players
Medium
23 people, a coin flip for a shared birthdayProbability · Monte Carlo · 10,000 rooms
Medium
An O(1) hash map, 1,354× slowerData structures · Hash table · 4,096 buckets
Medium
Reels
Reel · Quant & puzzles · 13 Nov 2026Planetary Parade, part 4: The tower twist
Reel · Quant & puzzles · 13 Nov 2026Planetary Parade, part 3: Your odds are 1 in 44
Reel · Quant & puzzles · 13 Nov 2026Planetary Parade, part 2: 7 circles, 44 skies
Reel · Quant & puzzles · 13 Nov 2026Planetary Parade, part 1: The puzzle I couldn't even readReelReel · Quant & puzzles · 12 Nov 2026What happens to the stock after a CEO scandal?