There are four blood types, and not all are equally likely to be in blood banks. In a certain blood bank, 49% of
donations are type O blood, 27% of donations are type
A blood, 20% of donations are type B blood, and 4%
of donations are type AB blood. A blood bank wants to
know how many donations will be required, on
average, to achieve at least one of each of the blood
types.
is it appropriate to use the geometric distribution to calculate probabilities in the situation?