Students in a middle school must choose to take either band or chorus. in a given academic year, 60% of the pupils choose band and the rest choose chorus. 30% of the students who are taking band are girls, and 70% who are taking chorus are girls. if a student is randomly selected from this academic year, what is the probability that it is a boy? a) 0.46 b) 0.49 c) 0.50 d) 0.54