Question

120 168 290 380 728 chose the no which is different from others in the group

Answer 1

Each of the numbers except 380, is either one less or one more than the square of a certain number.
112 – 1 = 120; 132 – 1 = 168; 172 + 1 = 290; 272 – 1 = 728.
So, Answer ...=380