The three circles in the diagram have the same centre and have radii 3cm, 4cm and 5cm.
What percentage of the area of the largest circle is shaded?
Sign in or create an account to reveal answers, view the solution, and save your progress. Create a free account to unlock practice and keep track of your work.
Intermediate Mathematical Challenge 1999 (1999)
One puzzle per day. Cryptarithm, Magic Square, Summit. No sign-up required to play.
Play daily puzzle →Interactive problems and curated lessons—water pouring, magic squares, knight's tour, and more.
Browse library →See how you rank. Top solvers by problems solved correctly. Sign in to climb the ranks.
View leaderboard →Intermediate Mathematical Challenge 1999 (1999)