Multiple choice general knowledge math & puzzles

A, B, C and D are four towns, any three of which are non -collinear. The number of ways to construct three roads each joining a pair of towns so that the roads do not form a triangle is:

  1. 7

  2. 8

  3. 9

  4. more than 9

Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

There are 6 possible roads between 4 towns. We must choose 3 roads such that no triangle is formed. Total ways to choose 3 roads is 20. There are 4 possible triangles. Thus, 20 - 4 = 16 ways. This is 'more than 9'.