Select the option that is related to the third number in the same way as the second number is related to the first number. 18 : 323 :: 24 : ?

625 575 675 535

575

Pattern followed is : (1st term)2 - 1 = 2nd term 18 : 323 (18)2 - 1 = 324 - 1 = 323  Similarly , 24 : ? (24)2 - 1 = 576 - 1 = 575 575 , is correct answer .