Question

a boy gives his classmates an equal number of candy bars. he tell s his friends that if five fewer kids show up next time, they will get two more candies each. instead, four more kids show up so they get one less candy a piece instead. how many candies each did the kids get on the second day?
Lisa
Do I base the equation on the number of kids in the class or the number of candy bars? or do I use x and y?