NDA 2025
- Exam
- NDA
- Year
- 2025
- Subject
- Mathematics
- Chapter
- Permutation and Combination
NDA 2025 · Mathematics · Permutation and Combination
For the following two (02) items: There are 8 points on a plane out...
For the following two (02) items:
There are 8 points on a plane out of which 4 points are collinear.
How many quadrilaterals can be formed by joining these points?
There are 8 points on a plane out of which 4 points are collinear.
How many quadrilaterals can be formed by joining these points?
Options
- A
- B
- C
- DNone of the above
Correct answer
C.
Step-by-step solution
Total number of points is .
Number of collinear points is .
Total number of ways to select points from points is ^{8}C_{4} = 70 or selected points are collinear.
Number of ways to select collinear points is ^{4}C_{4} = 1 collinear points and non-collinear point is ^{4}C_{3} \times ^{4}C_{1} = 4 \times 4 = 16.
Answer:
Number of collinear points is .
Total number of ways to select points from points is ^{8}C_{4} = 70 or selected points are collinear.
Number of ways to select collinear points is ^{4}C_{4} = 1 collinear points and non-collinear point is ^{4}C_{3} \times ^{4}C_{1} = 4 \times 4 = 16.
Answer: