lloyd = {
  "name": "Lloyd",
  "homework": [90.0, 97.0, 75.0, 92.0],
  "quizzes": [88.0, 40.0, 94.0],
  "tests": [75.0, 90.0]
}
alice = {
  "name": "Alice",
  "homework": [100.0, 92.0, 98.0, 100.0],
  "quizzes": [82.0, 83.0, 91.0],
  "tests": [89.0, 97.0]
}
tyler = {
  "name": "Tyler",
  "homework": [0.0, 87.0, 75.0, 22.0],
  "quizzes": [0.0, 75.0, 78.0],
  "tests": [100.0, 100.0]
}

# Add your function below!
def average(numbers):
  total = sum(numbers)
  return float(total) / len(numbers)

students = [lloyd, alice, tyler]

def get_average(student):
  homework = .1*(average(student["homework"]))
  quizzes = .3*(average(student["quizzes"]))
  tests = .6*(average(student["tests"]))

  score = homework + quizzes + tests
  return score

def get_letter_grade(score):
  if (score >= 90):
    return "A"
  elif (score >= 80):
    return "B"
  elif (score >= 70):
    return "C"
  elif (score >= 60):
    return "D"
  else:
    return "F"

print get_letter_grade(get_average(lloyd))

def get_class_average(class_list):
  results = []
  for student in class_list:
    student_av = get_average(student)
    results.append(student_av)
  return average(results)

students = [alice, lloyd, tyler]
print get_class_average(students)