There are 3 ants at 3 corners of a triangle, they randomly start moving towards another corner. What is the probability that they don’t collide?

prob of colliding is
= 1st and 2nd moving towards each other + 2nd and 3rd moving towards each other + 3rd and 1st moving towards each other
= (1/2)* (1/2) + (1/2)* (1/2) + (1/2)* (1/2) = 3/4

probability of not colliding = 1- 3/4 = 1/4