In an examination the percentage of students qualified to the number of students appeared from school A is 70%. In school B, the number of students appeared is 20% more than the student appeared from school A and the number of students qualified from school B is 50% more than the students qualified from school A. What is the percentage of students qualified to the number of students appeared from school B? `30 %` b. `70 %` c. `78. 5 %` d. 87.5%