For this question, why can’t we use the following approach-
Since we want red ball at a fifth place that means balls before these are either green or blue and we have 8 such balls that are not red so we could write the probability as 8/127/116/105/94/8 = 7/99
This basically means that for first four places since you are taking out the balls without replacement the denominator is decreasing and till 4th place its all red balls and soon as you arrive at the fifth place you have 4 red balls to choose from
In the explanation Greg says that no matter when you draw the red ball its probability is going to be same as when you first draw it which is 4/12 but I am unable to understand it like what all cases would you make to prove that?
