input: Write a Python function to check if the sum of two numbers is a multiple of 5.
  assert isMultipleOf5(10, 5) == True
  assert isMultipleOf5(2, 3) == True
  assert isMultipleOf5(7, 2) == False
output: def isMultipleOf5(a, b):
      return (a + b) % 5 == 0