For A. You would find 25% of 720 which is 25 so that be your answer. ((25 students are in band))
For B. You would find 32% of 720 which is 32 so that be your answer ((32 students riding the bus to school.))
For C. You would say something along the lines of... The information does not give any specific category for all of the students of the school to participate in.,