input: Write a python function to filter prime numbers from a list.
  assert filterPrimes([2, 3, 4, 5, 6, 7, 8, 9, 10])==[2, 3, 5, 7]
  assert filterPrimes([11, 12, 13, 14, 15, 16, 17, 18, 19, 20])==[11, 13, 17, 19]
  assert filterPrimes([4, 6, 8, 9, 10, 15, 21])==[]
output: def filterPrimes(numbers):
      def is_prime(n):
          if n <= 1:
              return False
          for i in range(2, int(n**0.5) + 1):
              if n % i == 0:
                  return False
          return True
  
      return [num for num in numbers if is_prime(num)]