Explanation:

Here the given number series 625, 625, 600, ?, 475, 875 follows a pattern that

625

625 + (0 x 0) = 625

625 - (5 x 5) = 625 - 25 = 600

600 + (10 x 10) = 600 + 100 = 700

700 - (15 x 15) = 700 - 225 = 475

475 + (20 x 20) = 475 + 400 = 875

Hence, the missing number in the given number series is 700.

Hence, option 2 is the correct answer.