input: Write a python function to find if there exists any pair of numbers in the list that adds up to a given target.
  assert find_pair([1, 2, 3, 4, 5], 9) == True
  assert find_pair([1, 2, 3, 4, 5], 10) == False
  assert find_pair([10, 20, 30, 40, 50], 70) == True
output: def find_pair(numbers, target):
      seen = set()
      for number in numbers:
          if target - number in seen:
              return True
          seen.add(number)
      return False