input: Write a python function to count numbers in a list that are divisible by 3.
  assert number_divisible_by_3([1, 2, 3, 4, 5, 6, 7, 8, 9, 10]) == 3
  assert number_divisible_by_3([10, 20, 45, 67, 84, 93]) == 3
  assert number_divisible_by_3([5, 7, 9, 8, 6, 4, 3]) == 3
output: def number_divisible_by_3(lst):
      return sum(1 for x in lst if x % 3 == 0)