input: Write a python function to check if any pair of numbers in a list of tuples sums to 10.
  assert checkSum([(2, 8), (4, 6), (7, 3)]) == True
  assert checkSum([(1, 2), (3, 4), (5, 6)]) == False
  assert checkSum([(10, 0), (0, 10), (5, 5)]) == True
output: def checkSum(lst):
      for a, b in lst:
          if a + b == 10:
              return True
      return False