input: Write a python function to create a string that summarizes a student's information.
  assert student_summary("John", 15, 90) == "Name: John, Age: 15, Marks: 90"
  assert student_summary("Alice", 20, 85) == "Name: Alice, Age: 20, Marks: 85"
  assert student_summary("Bob", 17, 78) == "Name: Bob, Age: 17, Marks: 78"
output: def student_summary(name, age, marks):
      return f"Name: {name}, Age: {age}, Marks: {marks}"