input: Write a function to find the sum of the multiples of 3 and 5 that are less than or equal to a given number.
  assert findSumOfMultiples(10) == 33
  assert findSumOfMultiples(20) == 98
  assert findSumOfMultiples(15) == 60
output: def findSumOfMultiples(n):
      return sum(x for x in range(n+1) if x % 3 == 0 or x % 5 == 0)