To solve, since 25% bring their lunch we can assume 75% do not bring their lunch from school.
225 is the 75% so to solve we do an equation as such:
x(.75) = 225
x = 225/.75
x = 300
Therefore there are 300 students at the school
You can use a double bar graph to draw the diagram, using the left y axis as percent, and the right y axis as number
Now we have 25% of 300 who bring their lunches which equals 75 students
