3. There are 10 counters in a bag, 6 are blue and 4 are yellow. Mary, Joe and Alice select a counter each. Mary goes first then Joe and finally Alice. Each time a counter is selected it is not replaced.

Calculate the probability that: (You may want to use a probability tree for all parts of this question) a) Mary, Joe and Alice all select Yellow counters.
b) No blue counters are selected.
c) That Mary selects a blue counter and the others get yellow.
d) That there is at least 1 yellow counter left after all three selections.​