Correct option is D
Given:
625, 600, 575, 550, 525, ?
Logic: In the given series 25 is decreasing from each number.
So, the next number :
625 – 600 = 25
600 – 575 = 25
575 – 550 = 25
550 - 525 = 25
525 - 25 = 500
Thus, correct option is (d).