Which of the following numbers will replace the question mark (?) and complete the given number series

Which of the following numbers will replace the question mark (?) and complete the given number series?
600, 590, 575, 550, 510, ?
A. 460
B. 450
C. 440
D. 420
Sol:
Pattern follows here is -10, -15, -25, -40, -60
So, the next required term 510-60=450