NA

∵ 272 = 2 + 7 + 2 = 11
210 = 2 + 1 + 0 = 3
240 = 2 + 4 + 0 = 6
304 = 3 + 0 + 4 = 7
The sum of digit of all number except 240 is a prime number where as sum of number 240 digit is a non-prime. Hence, it is different from all others.