You have 4 colored balls in a bag.
1) red
2) red
3) blue
4) yellow
You take 2 balls out.
Look at only one.
It is red.
What are the odds that the other ball is red?
1 in 6
possible combos;
blue red1
blue red2
blue yellow
red1 red2
red1 yellow
red2 yellow
OR
1 in 3
red chosen so blue , red , yellow are left
OR
1 in 4
possible combos;
blue red
blue yellow
red red
red yellow
OR
1 in 5
possible combos;
red1 blue
red1 yellow
red2 blue
red2 yellow
red1 red2
Which is correct?