The Principal of Jimbo’s school interviewed 30% of the 8th graders at recess about the food fight yesterday. The Assistant Principal grabbed 40% of the 8th graders at lunchtime to investigate the disappearance of all of the blackboard erasers. Fortunately for Jimbo, he was in the 50% of the 8th graders that escaped without an interview. If twenty-five 8th graders had to front only the Principal, how many students are in the 8th grade at Jimbo’s school?
Answer
Since 50% had no interview, then 50% did have an interview. But the Principal and the Assistant Principal together interviewed 40% + 30% = 70%. That means 20% of the 8th graders were interviewed twice. That leaves 10% who fronted only the Principal. Thus there are 250 students in the 8th grade at Jimbo’s school.