input: Write a function to remove elements from a list that are divisible by a given number.
  assert remove_divisible([7, 8, 15, 21, 24], 3) == [7, 8, 21]
  assert remove_divisible([10, 20, 30, 40, 50], 10) == []
  assert remove_divisible([12, 18, 25, 40, 55], 5) == [12, 18]
  assert remove_divisible([6, 9, 15, 20, 25, 30], 4) == [6, 9, 15, 25]
output: def remove_divisible(lst, num):
      return [x for x in lst if x % num != 0]