I have 6 pieces of candy: two each of 3 different colors. They taste especially good if eaten two at a time, provided the colors are different.
These candies are in an opaque bag from which I pick two at a time. If they are different colors I eat them together (yum) but if they are the same I put them back in and draw again. I will repeat this process to eat two more.
What is the probability the last two candies will be of differing colors?
Repeat with two each of 4 colors.
Repeat with two each of 5 colors.
Once I've eaten the first par of candies there are four candies lasting from three different colors (a,b,c:,c).
When I pick the next two candies I will eat when I pick:
ab, ac:, ac, ba, bc:, bc, c:a, c:b, ca, cb.
If I pick ab o ba the candies lasting in the bag are c: and c (same color).
So the probablility that the last two candies are of different colors is 8/10 = 0.8.

Posted by armando
on 20160525 09:10:26 