for this code in the output Im getting a none I cannot understand the reason

Question

''' I'm getting none in the output along with the answers in this python program'''

class marks1():
  def __init__(x,name,class1,*marks):
    x.name = name
    x.class1 = class1
    x.marks = sum(marks)

  def nameclass(x):
    print( "{} belongs to class{}".format(x.name,x.class1))
 
  def marksavg(x):
    avg= x.marks/5
    return avg

n = marks1("janani","6-B",92,87,75,88,90)
print(n.nameclass())
print(n.marksavg())