150 students at York Middle School took part in the school clean up. This is 30% of

the school's total students. How many students go to York Middle School?

500 students.

Step-by-step explanation:

Since 150 students make up 30% of the school's student population, the equation 150/30=x/100. In order to find x, cross multiply x*30 and 150*100. Then set the two results equal to each other and solve. 15000=30x. 15000/30=500. x=500.