The Old techInterview Forum - ants on a triangle ---- A simple solution

ants on a triangle ---- A simple solution

Ant A start to move in either one direction (clockwise or counter), the probability is 1;
Ant B moves in the same direction as A, probability is 1/2;
Ant C moves in the same direction as A, probability is 1/2;

3 ants move in the same direction, the probability is:

1*(1/2)*(1/2) = 1/4 = 0.25

Pan, Wenyu
Friday, September 20, 2002