Proofreading Mistakes
If proofreader 
finds 
mistakes and proofreader 
finds 
mistakes, 
of which were also found by , how manymistakes were missed by both and ? Assume there are a total of 
mistakes, so proofreader finds a Fraction
of all mistakes, and also a Fraction 
of the mistakes found by . Assuming these fractions are the same,then solving for gives
The number of mistakes missed by both is therefore approximately
References
Pólya, G. ``Probabilities in Proofreading.'' Amer. Math. Monthly, 83, 42, 1976.
- Tangent Hyperbolas Method
- Tangential Angle
- Tangential Triangle
- Tangential Triangle Circumcenter
- Tangent Indicatrix
- Tangent Line
- Tangent Map
- Tangent Number
- Tangent Plane
- Tangents Law
- Tangent Space
- Tangent Vector
- Tangle
- Tanglecube
- Tangled Hierarchy
- Tangram
- Tanh
- Taniyama Conjecture
- Taniyama-Shimura Conjecture
- Tank
- Tantrix
- Tapering Function
- Tarry-Escott Problem
- Tarry Point
- Tarski's Theorem