A group of 15 youngsters received 5 tickets to a rock happening.
The lucky recipients were determined by a random drawing of names
(no replacement) from a closed bag.
Although there were only 6 girls in the group they jointly received more tickets than the boys.
a. What is the a priori probability of such partition?
b. What would be the result if the drawing was performed with replacements?
c. Define the meaning of the difference b-a.