NDA 2021
- Exam
- NDA
- Year
- 2021
- Subject
- Mathematics
- Chapter
- Permutation and Combination
NDA 2021 · Mathematics · Permutation and Combination
Suppose 20 distinct points are placed randomly on a circle. Which...
Suppose 20 distinct points are placed randomly on a circle.
Which of the following statements is/are correct?
1. The number of straight lines that can be drawn by joining any two of these points is 380.
2. The number of triangles that can be drawn by joining any three of these points is 1140.
Select the correct answer using the code given below.
Options
- A1 only
- B2 only
- CBoth 1 and 2
- DNeither 1 nor 2
Correct answer
B. 2 only
Step-by-step solution
Number of St lines
Number of triangles