The average class size at belmont middle school is 30 students, which is 25% larger than it was a decade ago. what was the average class size then?

One cell phone plan charges $20 per month plus $0.15 per minute used. a second cell phone plan charges $35 per month plus $0.10 per minute used. write and solve an equation to find the number of minutes you must talk to have the same cost for both calling plans.