Level 10: Mental math & market-making
Fermi estimation, fast arithmetic, expected-value games, and making two-sided markets — the trading-floor reflexes that prop and market-making firms screen for.
12 problems
First 2 free · rest Premium
- 1→
How Many Piano Tuners?
●●●○○Medium~6 min
- 2→
Squaring in Your Head
●●○○○Easy~4 min
- 3Premium
Make Me a Market
●●●●○Hard~7 min
- 4Premium
Pricing a Card Draw
●●●○○Medium~5 min
- 5Premium
Why Spreads Exist
●●●●○Hard~7 min
- 6Premium
What's a Peek Worth?
●●●○○Medium~5 min
- 7Premium
Trailing Zeros of 100!
●●●○○Medium~5 min
- 8Premium
Powers of Two and Ten
●●○○○Easy~4 min
- 9Premium
The Rule of 72
●●○○○Easy~4 min
- 10Premium
Should You Play?
●●○○○Easy~4 min
- 11Premium
Skewing Quotes for Inventory
●●●●○Hard~6 min
- 12Premium
Sizing a Market
●●●○○Medium~6 min