In one urn there are 10 white balls 18 red balls 6 green balls

A1) What is the probability of drawing a red ball for the first time on the third move if it is not replaced? Define the random variable for this random experiment

A2. Now 20 balls are drawn with Put back. b1) What is the probability that only the first three balls are red?

A3. Calculate the probability that a red ball will be drawn more than four times but less than six times

A4. A blue ball is added to the urn from a1). What is the likelihood of drawing a red ball if you know - from wherever - that it can't be green? Give reasons for your answer