I hope you did not actually waste time doing that in your head.
You can see X=M for both years, you can totally ignore that.
Mentally add 500+200+300 = 1000, easy.
Mentally add 550+250+300, = 1100, easy. (You know the last one was 1000, there's two new 50s here).
1100 / 110 = 1
(A)
Did it...