input: Write a python function to check if numbers in a list are divisible by 3 and return a list of such numbers.
  assert filter_divisible_by_3([3, 6, 9, 12, 15, 20, 25, 30]) == [3, 6, 9, 12, 15, 30]
  assert filter_divisible_by_3([1, 2, 4, 5, 7, 8, 10]) == []
  assert filter_divisible_by_3([3, 33, 39, 42, 45, 48]) == [3, 33, 39, 42, 45, 48]
output: def filter_divisible_by_3(numbers):
      return [num for num in numbers if num % 3 == 0]