I do not get this i will give you brainlist and all my points

School has 204 sixth grade students. if the sixth grade is 30% of the total school, how many students are in the middle school?

Which function has an inverse that is also a function? a.{(-4,3), (-2, 7), (-1,0), (4, -3), (11, -7)} b.{(-4, 6), (-2, 2), (-1, 6), (4,2), (11, 2)} c.{(-4,5), (-2, 9), (-1,8), (4, 8), (11,4)} d.{(-4,4), (-2, -1), (-1,0), (4, 1), (11, 1)}

On the blueprint of a house, 42 millimeters represents 8 meters. the actual lehenth of the living room is 5 meters. what is the length on the blueprint