If three of the six vertices of a regular hexagon are chosen at random, then the probability that the triangle formed with these chosen vertices is equilateral is?

Correct option is B. 1/10
Step 1: Calculating number of ways and total outcomes
The probability of choosing 3 vertices in random so that they form an equilateral triangle
Total number of outcome = 6C3 = 20
Number of favourable outcome = We can't choose adjacent vertices as they won't form an equilateral triangle. We choose alternate vertices.
∴ Number of ways of choosing = 2
Step 2: Calculating probability
Probability = Number of favourable outcomes / Total number of outcomes
∴ 2/20 = 1/10
Hence, The required probability = 1/10