input: Write a function to generate an even number between 10 and 200 that is divisible by 5. If no such number exists, return None.
  
  def generate_even_number():
   num = random.randint(10, 200)
   if num % 2 == 0:
    if num % 5 == 0:
     return num
    else:
     return generate_even_number(num+1)
   else:
     return generate_even_number(num+1)
  
  assert generate_even_number() % 2 == 0
  assert generate_even_number() % 5 == 0
  assert generate_even_number() >= 10
  assert generate_even_number() <= 200
output: def generate_even_number():
      num = random.randint(10, 200)
      if num % 2 == 0 and num % 5 == 0:
          return num
      else:
          return generate_even_number()