70% of the 100 students in a middle school cafeteria bought their lunch. Some of the students that bought there lunch leave the cafeteria to attend a assembly. Now only 60% of the remaining students bought there lunch. How many students are remaining in the cafeteria? Explain.

600 because 60 percent of 100 is 600

70% of 100 is 70and 60% of 100 is 60.

70% bought lunch and 30% didnt, so that means 79 bought lunch and 30 didn't. onky people who bought lunch left, so the 30% remained. but 60% of the students bought lunch stayed in the cafeteria. 30%+60%=90%. 90% is 90 students, so there are 90 students in the cafeteria