question: Find the room number of the rooms which can sit 50 to 100 students and their buildings.
#1 return rooms 
#2 return #1 that  sit at least 50 students 
#3 return #1 that  sit at most 100 students 
#4 return #1 in both #2 and #3 
#5 return room number of  #4 
#6 return buildings of  #4 
#7 return #5 ,   #6