NDA2026MathematicsPermutation and CombinationActual
What is the maximum number of points of intersection of 5 circles ?
Options
- A10
- B15
- C20
- D25
Correct answer
C. 20
Step-by-step solution
Two circles can intersect at a maximum of 2 distinct points. To find the maximum number of points of intersection of 5 circles, we select any 2 circles from the given 5 circles and multiply the number of pairs by 2 . The number of ways to select 2 circles from 5 is ⁵C₂ . Maximum number of points of intersection = 2 ⁵C₂ = 2 5 4 2 1 = 20 Answer: 20