Question
Question: If PQRS is a convex quadrilateral with 3, 4, 5, & 6 points marked on sides PQ, QR, RS and PS respect...
If PQRS is a convex quadrilateral with 3, 4, 5, & 6 points marked on sides PQ, QR, RS and PS respectively, then the number of triangles with vertices on different sides is
A
220
B
270
C
282
D
342
Answer
342
Explanation
Solution
no. of triangles
= 3C1. 4C1.5C1 + 4C1.5C1.6C1 + 5C1. 6C1. 3C1 + 6C1. 3C1. 4C1
= 60 +120 + 90 + 72
= 342