A group of 5 boys and 4 girls take part in a study on the type of plants found in a reserved forest area. Each day, two pupils are chosen at random to write a report.
a) Calculate the probability that both pupils chosen to write the report on the first day are boys.
b) Two boys wrote the report on the first day. They are then exempted from writing the report on the second day.
Calculate the probability that both pupils chosen to write the report on the second day are of the same gender.