Finley’s pumpkin had a mass of 6.5 kg before he carved it. after carving it, the pumpkin had a mass of 3.9 kg. what was the percent decrease in the mass of the pumpkin?

While on a train trip, marsha noticed that there were 35 people in her train car. after the next stop, there were only 21 people in her car. if p represents the percent decrease in the number of people in marsha's train car, what is p?