用計算器按了幾下, 得到

Just kidding.  A= 50^50, B=49^51, C=51^49

A/B=(1/49)*(50/49)^50=(1/49)*(1+1/49)^50=~(1/49)*2<1

C/A=(1/50)*(51/50)^49=(1/50)*(1+0.02)^49=~(1/50)*2<1

B>A>C