I still cant figure this question out 2M can be replaced by 2B =Sufficient 1M can be replaced by 1B =insufficient The question seems to not have asked for either but for sufficiency. I don't know what am missing 9M+ 9B = 15 7M+11B = 15 2M-2B 10M+8B = 15 -M+B I still see both being independently able...