Question

设a＞b＞c,n∈N,且+≥,则n的最大值为(    )

A.2              B.3                   C.4                    D.5

Answer 1

C

解析:设a-b=x,b-c=y,则x＞0,y＞0.

∴a-c=x+y,故原不等式可化为+≥.

∴n≤2++.而2++≥4,∴n_max=4.