CAT 1999 — QA Question 4
Geometry based questionsEasy
Ten points are marked on a straight-line and 11 points are marked on another straight-line. How many triangles can be constructed with vertices from among the above points?
Answer & solution
- A
495
- B
550
1045
- D
2475
Solution
The answer is 10C2 × 11 + 11C2 × 10 = 45 × 11 + 55 x 10 = 1045.
Hence, option (c).