Inside the inner circle

A point is chosen uniformly at random inside a disk of radius 1. What is the probability it lies within distance 12\tfrac12 of the center?

Show hints (2)+
  1. Uniform over area, so compare areas.
  2. Area scales with radius squared.

Answer

Reveal answer →

0.25

Want the full step-by-step worked solution? It's part of Premium — along with a worked solution for every question in the bank.

Asked at: Optiver, IMC

Related questions