Question
Question: The sides AB, BC, CA of a triangle ABC have 3, 4 and 5 interior points respectively on them. The tot...
The sides AB, BC, CA of a triangle ABC have 3, 4 and 5 interior points respectively on them. The total number of triangles that can be constructed by using these points as vertices is
A
220
B
204
C
205
D
195
Answer
205
Explanation
Solution
Ds = 12C3 – 3C3 – 4C3 – 5C3
= 220 – 1 – 4 – 10
= 205