From 15 non-collinear points in a plane, how many distinct straight lines can be drawn using pairs of points?

Introduction / Context:Each pair of non-collinear points defines a unique line. With no three collinear, distinct pairs yield distinct lines.

Given Data / Assumptions:

• 15 points; no three are collinear.

Concept / Approach:Count pairs: C(15, 2).

Step-by-Step Solution:

Verification / Alternative check:The non-collinearity ensures no pair duplicates an existing line.

Why Other Options Are Wrong:120, 110, 115 are not equal to C(15, 2).

Common Pitfalls:Forgetting the “no three collinear” condition; otherwise some pairs could lie on the same line and reduce the count.

Final Answer:105